import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

mobile/android/base/java/org/mozilla/gecko/db/AbstractPerProfileDatabaseProvider.java

@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.annotation.RobocopTarget;
+
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.net.Uri;
+
+/**
+ * The base class for ContentProviders that wish to use a different DB
+ * for each profile.
+ *
+ * This class has logic shared between ordinary per-profile CPs and
+ * those that wish to share DB connections between CPs.
+ */
+public abstract class AbstractPerProfileDatabaseProvider extends AbstractTransactionalProvider {
+
+    /**
+     * Extend this to provide access to your own map of shared databases. This
+     * is a method so that your subclass doesn't collide with others!
+     */
+    protected abstract PerProfileDatabases<? extends SQLiteOpenHelper> getDatabases();
+
+    /*
+     * Fetches a readable database based on the profile indicated in the
+     * passed URI. If the URI does not contain a profile param, the default profile
+     * is used.
+     *
+     * @param uri content URI optionally indicating the profile of the user
+     * @return    instance of a readable SQLiteDatabase
+     */
+    @Override
+    protected SQLiteDatabase getReadableDatabase(Uri uri) {
+        String profile = null;
+        if (uri != null) {
+            profile = uri.getQueryParameter(BrowserContract.PARAM_PROFILE);
+        }
+
+        return getDatabases().getDatabaseHelperForProfile(profile, isTest(uri)).getReadableDatabase();
+    }
+
+    /*
+     * Fetches a writable database based on the profile indicated in the
+     * passed URI. If the URI does not contain a profile param, the default profile
+     * is used
+     *
+     * @param uri content URI optionally indicating the profile of the user
+     * @return    instance of a writable SQLiteDatabase
+     */
+    @Override
+    protected SQLiteDatabase getWritableDatabase(Uri uri) {
+        String profile = null;
+        if (uri != null) {
+            profile = uri.getQueryParameter(BrowserContract.PARAM_PROFILE);
+        }
+
+        return getDatabases().getDatabaseHelperForProfile(profile, isTest(uri)).getWritableDatabase();
+    }
+
+    protected SQLiteDatabase getWritableDatabaseForProfile(String profile, boolean isTest) {
+        return getDatabases().getDatabaseHelperForProfile(profile, isTest).getWritableDatabase();
+    }
+
+    /**
+     * This method should ONLY be used for testing purposes.
+     *
+     * @param uri content URI optionally indicating the profile of the user
+     * @return    instance of a writable SQLiteDatabase
+     */
+    @Override
+    @RobocopTarget
+    public SQLiteDatabase getWritableDatabaseForTesting(Uri uri) {
+        return getWritableDatabase(uri);
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/AbstractTransactionalProvider.java

@@ -0,0 +1,328 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.AppConstants.Versions;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+/**
+ * This abstract class exists to capture some of the transaction-handling
+ * commonalities in Fennec's DB layer.
+ *
+ * In particular, this abstracts DB access, batching, and a particular
+ * transaction approach.
+ *
+ * That approach is: subclasses implement the abstract methods
+ * {@link #insertInTransaction(android.net.Uri, android.content.ContentValues)},
+ * {@link #deleteInTransaction(android.net.Uri, String, String[])}, and
+ * {@link #updateInTransaction(android.net.Uri, android.content.ContentValues, String, String[])}.
+ *
+ * These are all called expecting a transaction to be established, so failed
+ * modifications can be rolled-back, and work batched.
+ *
+ * If no transaction is established, that's not a problem. Transaction nesting
+ * can be avoided by using {@link #beginWrite(SQLiteDatabase)}.
+ *
+ * The decision of when to begin a transaction is left to the subclasses,
+ * primarily to avoid the pattern of a transaction being begun, a read occurring,
+ * and then a write being necessary. This lock upgrade can result in SQLITE_BUSY,
+ * which we don't handle well. Better to avoid starting a transaction too soon!
+ *
+ * You are probably interested in some subclasses:
+ *
+ * * {@link AbstractPerProfileDatabaseProvider} provides a simple abstraction for
+ *   querying databases that are stored in the user's profile directory.
+ * * {@link PerProfileDatabaseProvider} is a simple version that only allows a
+ *   single ContentProvider to access each per-profile database.
+ * * {@link SharedBrowserDatabaseProvider} is an example of a per-profile provider
+ *   that allows for multiple providers to safely work with the same databases.
+ */
+@SuppressWarnings("javadoc")
+public abstract class AbstractTransactionalProvider extends ContentProvider {
+    private static final String LOGTAG = "GeckoTransProvider";
+
+    private static final boolean logDebug = Log.isLoggable(LOGTAG, Log.DEBUG);
+    private static final boolean logVerbose = Log.isLoggable(LOGTAG, Log.VERBOSE);
+
+    protected abstract SQLiteDatabase getReadableDatabase(Uri uri);
+    protected abstract SQLiteDatabase getWritableDatabase(Uri uri);
+
+    public abstract SQLiteDatabase getWritableDatabaseForTesting(Uri uri);
+
+    protected abstract Uri insertInTransaction(Uri uri, ContentValues values);
+    protected abstract int deleteInTransaction(Uri uri, String selection, String[] selectionArgs);
+    protected abstract int updateInTransaction(Uri uri, ContentValues values, String selection, String[] selectionArgs);
+
+    /**
+     * Track whether we're in a batch operation.
+     *
+     * When we're in a batch operation, individual write steps won't even try
+     * to start a transaction... and neither will they attempt to finish one.
+     *
+     * Set this to <code>Boolean.TRUE</code> when you're entering a batch --
+     * a section of code in which {@link ContentProvider} methods will be
+     * called, but nested transactions should not be started. Callers are
+     * responsible for beginning and ending the enclosing transaction, and
+     * for setting this to <code>Boolean.FALSE</code> when done.
+     *
+     * This is a ThreadLocal separate from `db.inTransaction` because batched
+     * operations start transactions independent of individual ContentProvider
+     * operations. This doesn't work well with the entire concept of this
+     * abstract class -- that is, automatically beginning and ending transactions
+     * for each insert/delete/update operation -- and doing so without
+     * causing arbitrary nesting requires external tracking.
+     *
+     * Note that beginWrite takes a DB argument, but we don't differentiate
+     * between databases in this tracking flag. If your ContentProvider manages
+     * multiple database transactions within the same thread, you'll need to
+     * amend this scheme -- but then, you're already doing some serious wizardry,
+     * so rock on.
+     */
+    final ThreadLocal<Boolean> isInBatchOperation = new ThreadLocal<Boolean>();
+
+    private boolean isInBatch() {
+        final Boolean isInBatch = isInBatchOperation.get();
+        if (isInBatch == null) {
+            return false;
+        }
+
+        return isInBatch;
+    }
+
+    /**
+     * If we're not currently in a transaction, and we should be, start one.
+     */
+    protected void beginWrite(final SQLiteDatabase db) {
+        if (isInBatch()) {
+            trace("Not bothering with an intermediate write transaction: inside batch operation.");
+            return;
+        }
+
+        if (!db.inTransaction()) {
+            trace("beginWrite: beginning transaction.");
+            db.beginTransaction();
+        }
+    }
+
+    /**
+     * If we're not in a batch, but we are in a write transaction, mark it as
+     * successful.
+     */
+    protected void markWriteSuccessful(final SQLiteDatabase db) {
+        if (isInBatch()) {
+            trace("Not marking write successful: inside batch operation.");
+            return;
+        }
+
+        if (db.inTransaction()) {
+            trace("Marking write transaction successful.");
+            db.setTransactionSuccessful();
+        }
+    }
+
+    /**
+     * If we're not in a batch, but we are in a write transaction,
+     * end it.
+     *
+     * @see PerProfileDatabaseProvider#markWriteSuccessful(SQLiteDatabase)
+     */
+    protected void endWrite(final SQLiteDatabase db) {
+        if (isInBatch()) {
+            trace("Not ending write: inside batch operation.");
+            return;
+        }
+
+        if (db.inTransaction()) {
+            trace("endWrite: ending transaction.");
+            db.endTransaction();
+        }
+    }
+
+    protected void beginBatch(final SQLiteDatabase db) {
+        trace("Beginning batch.");
+        isInBatchOperation.set(Boolean.TRUE);
+        db.beginTransaction();
+    }
+
+    protected void markBatchSuccessful(final SQLiteDatabase db) {
+        if (isInBatch()) {
+            trace("Marking batch successful.");
+            db.setTransactionSuccessful();
+            return;
+        }
+        Log.w(LOGTAG, "Unexpectedly asked to mark batch successful, but not in batch!");
+        throw new IllegalStateException("Not in batch.");
+    }
+
+    protected void endBatch(final SQLiteDatabase db) {
+        trace("Ending batch.");
+        db.endTransaction();
+        isInBatchOperation.set(Boolean.FALSE);
+    }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+        trace("Calling delete on URI: " + uri + ", " + selection + ", " + selectionArgs);
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        int deleted = 0;
+
+        try {
+            deleted = deleteInTransaction(uri, selection, selectionArgs);
+            markWriteSuccessful(db);
+        } finally {
+            endWrite(db);
+        }
+
+        if (deleted > 0) {
+            final boolean shouldSyncToNetwork = !isCallerSync(uri);
+            getContext().getContentResolver().notifyChange(uri, null, shouldSyncToNetwork);
+        }
+
+        return deleted;
+    }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        trace("Calling insert on URI: " + uri);
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        Uri result = null;
+        try {
+            result = insertInTransaction(uri, values);
+            markWriteSuccessful(db);
+        } catch (SQLException sqle) {
+            Log.e(LOGTAG, "exception in DB operation", sqle);
+        } catch (UnsupportedOperationException uoe) {
+            Log.e(LOGTAG, "don't know how to perform that insert", uoe);
+        } finally {
+            endWrite(db);
+        }
+
+        if (result != null) {
+            final boolean shouldSyncToNetwork = !isCallerSync(uri);
+            getContext().getContentResolver().notifyChange(uri, null, shouldSyncToNetwork);
+        }
+
+        return result;
+    }
+
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        trace("Calling update on URI: " + uri + ", " + selection + ", " + selectionArgs);
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        int updated = 0;
+
+        try {
+            updated = updateInTransaction(uri, values, selection,
+                                          selectionArgs);
+            markWriteSuccessful(db);
+        } finally {
+            endWrite(db);
+        }
+
+        if (updated > 0) {
+            final boolean shouldSyncToNetwork = !isCallerSync(uri);
+            getContext().getContentResolver().notifyChange(uri, null, shouldSyncToNetwork);
+        }
+
+        return updated;
+    }
+
+    @Override
+    public int bulkInsert(Uri uri, ContentValues[] values) {
+        if (values == null) {
+            return 0;
+        }
+
+        int numValues = values.length;
+        int successes = 0;
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+
+        debug("bulkInsert: explicitly starting transaction.");
+        beginBatch(db);
+
+        try {
+            for (int i = 0; i < numValues; i++) {
+                insertInTransaction(uri, values[i]);
+                successes++;
+            }
+            trace("Flushing DB bulkinsert...");
+            markBatchSuccessful(db);
+        } finally {
+            debug("bulkInsert: explicitly ending transaction.");
+            endBatch(db);
+        }
+
+        if (successes > 0) {
+            final boolean shouldSyncToNetwork = !isCallerSync(uri);
+            getContext().getContentResolver().notifyChange(uri, null, shouldSyncToNetwork);
+        }
+
+        return successes;
+    }
+
+    /**
+     * Indicates whether a query should include deleted fields
+     * based on the URI.
+     * @param uri query URI
+     */
+    protected static boolean shouldShowDeleted(Uri uri) {
+        String showDeleted = uri.getQueryParameter(BrowserContract.PARAM_SHOW_DELETED);
+        return !TextUtils.isEmpty(showDeleted);
+    }
+
+    /**
+     * Indicates whether an insertion should be made if a record doesn't
+     * exist, based on the URI.
+     * @param uri query URI
+     */
+    protected static boolean shouldUpdateOrInsert(Uri uri) {
+        String insertIfNeeded = uri.getQueryParameter(BrowserContract.PARAM_INSERT_IF_NEEDED);
+        return Boolean.parseBoolean(insertIfNeeded);
+    }
+
+    /**
+     * Indicates whether query is a test based on the URI.
+     * @param uri query URI
+     */
+    protected static boolean isTest(Uri uri) {
+        if (uri == null) {
+            return false;
+        }
+        String isTest = uri.getQueryParameter(BrowserContract.PARAM_IS_TEST);
+        return !TextUtils.isEmpty(isTest);
+    }
+
+    /**
+     * Return true of the query is from Firefox Sync.
+     * @param uri query URI
+     */
+    protected static boolean isCallerSync(Uri uri) {
+        String isSync = uri.getQueryParameter(BrowserContract.PARAM_IS_SYNC);
+        return !TextUtils.isEmpty(isSync);
+    }
+
+    protected static void trace(String message) {
+        if (logVerbose) {
+            Log.v(LOGTAG, message);
+        }
+    }
+
+    protected static void debug(String message) {
+        if (logDebug) {
+            Log.d(LOGTAG, message);
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/BaseTable.java

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+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.util.Log;
+
+// BaseTable provides a basic implementation of a Table for tables that don't require advanced operations during
+// insert, delete, update, or query operations. Implementors must still provide onCreate and onUpgrade operations.
+public abstract class BaseTable implements Table {
+    private static final String LOGTAG = "GeckoBaseTable";
+
+    private static final boolean DEBUG = false;
+
+    protected static void log(String msg) {
+        if (DEBUG) {
+            Log.i(LOGTAG, msg);
+        }
+    }
+
+    // Table implementation
+    @Override
+    public Table.ContentProviderInfo[] getContentProviderInfo() {
+        return new Table.ContentProviderInfo[0];
+    }
+
+    // Returns the name of the table to modify/query
+    protected abstract String getTable();
+
+    // Table implementation
+    @Override
+    public Cursor query(SQLiteDatabase db, Uri uri, int dbId, String[] columns, String selection, String[] selectionArgs, String sortOrder, String groupBy, String limit) {
+        Cursor c = db.query(getTable(), columns, selection, selectionArgs, groupBy, null, sortOrder, limit);
+        log("query " + columns + " in " + selection + " = " + c);
+        return c;
+    }
+
+    @Override
+    public int update(SQLiteDatabase db, Uri uri, int dbId, ContentValues values, String selection, String[] selectionArgs) {
+        int updated = db.updateWithOnConflict(getTable(), values, selection, selectionArgs, SQLiteDatabase.CONFLICT_REPLACE);
+        log("update " + values + " in " + selection + " = " + updated);
+        return updated;
+    }
+
+    @Override
+    public long insert(SQLiteDatabase db, Uri uri, int dbId, ContentValues values) {
+        long inserted = db.insertOrThrow(getTable(), null, values);
+        log("insert " + values + " = " + inserted);
+        return inserted;
+    }
+
+    @Override
+    public int delete(SQLiteDatabase db, Uri uri, int dbId, String selection, String[] selectionArgs) {
+        int deleted = db.delete(getTable(), selection, selectionArgs);
+        log("delete " + selection + " = " + deleted);
+        return deleted;
+    }
+};

mobile/android/base/java/org/mozilla/gecko/db/BrowserContract.java

@@ -0,0 +1,785 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.AppConstants;
+
+import android.net.Uri;
+import android.support.annotation.NonNull;
+
+import org.mozilla.gecko.annotation.RobocopTarget;
+
+@RobocopTarget
+public class BrowserContract {
+    public static final String AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.browser";
+    public static final Uri AUTHORITY_URI = Uri.parse("content://" + AUTHORITY);
+
+    public static final String PASSWORDS_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.passwords";
+    public static final Uri PASSWORDS_AUTHORITY_URI = Uri.parse("content://" + PASSWORDS_AUTHORITY);
+
+    public static final String FORM_HISTORY_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.formhistory";
+    public static final Uri FORM_HISTORY_AUTHORITY_URI = Uri.parse("content://" + FORM_HISTORY_AUTHORITY);
+
+    public static final String TABS_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.tabs";
+    public static final Uri TABS_AUTHORITY_URI = Uri.parse("content://" + TABS_AUTHORITY);
+
+    public static final String HOME_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.home";
+    public static final Uri HOME_AUTHORITY_URI = Uri.parse("content://" + HOME_AUTHORITY);
+
+    public static final String PROFILES_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".profiles";
+    public static final Uri PROFILES_AUTHORITY_URI = Uri.parse("content://" + PROFILES_AUTHORITY);
+
+    public static final String READING_LIST_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.readinglist";
+    public static final Uri READING_LIST_AUTHORITY_URI = Uri.parse("content://" + READING_LIST_AUTHORITY);
+
+    public static final String SEARCH_HISTORY_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.searchhistory";
+    public static final Uri SEARCH_HISTORY_AUTHORITY_URI = Uri.parse("content://" + SEARCH_HISTORY_AUTHORITY);
+
+    public static final String LOGINS_AUTHORITY = AppConstants.ANDROID_PACKAGE_NAME + ".db.logins";
+    public static final Uri LOGINS_AUTHORITY_URI = Uri.parse("content://" + LOGINS_AUTHORITY);
+
+    public static final String PARAM_PROFILE = "profile";
+    public static final String PARAM_PROFILE_PATH = "profilePath";
+    public static final String PARAM_LIMIT = "limit";
+    public static final String PARAM_SUGGESTEDSITES_LIMIT = "suggestedsites_limit";
+    public static final String PARAM_TOPSITES_DISABLE_PINNED = "topsites_disable_pinned";
+    public static final String PARAM_IS_SYNC = "sync";
+    public static final String PARAM_SHOW_DELETED = "show_deleted";
+    public static final String PARAM_IS_TEST = "test";
+    public static final String PARAM_INSERT_IF_NEEDED = "insert_if_needed";
+    public static final String PARAM_INCREMENT_VISITS = "increment_visits";
+    public static final String PARAM_INCREMENT_REMOTE_AGGREGATES = "increment_remote_aggregates";
+    public static final String PARAM_EXPIRE_PRIORITY = "priority";
+    public static final String PARAM_DATASET_ID = "dataset_id";
+    public static final String PARAM_GROUP_BY = "group_by";
+
+    static public enum ExpirePriority {
+        NORMAL,
+        AGGRESSIVE
+    }
+
+    /**
+     * Produces a SQL expression used for sorting results of the "combined" view by frecency.
+     * Combines remote and local frecency calculations, weighting local visits much heavier.
+     *
+     * @param includesBookmarks When URL is bookmarked, should we give it bonus frecency points?
+     * @param ascending Indicates if sorting order ascending
+     * @return Combined frecency sorting expression
+     */
+    static public String getCombinedFrecencySortOrder(boolean includesBookmarks, boolean ascending) {
+        final long now = System.currentTimeMillis();
+        StringBuilder order = new StringBuilder(getRemoteFrecencySQL(now) + " + " + getLocalFrecencySQL(now));
+
+        if (includesBookmarks) {
+            order.insert(0, "(CASE WHEN " + Combined.BOOKMARK_ID + " > -1 THEN 100 ELSE 0 END) + ");
+        }
+
+        order.append(ascending ? " ASC" : " DESC");
+        return order.toString();
+    }
+
+    /**
+     * See Bug 1265525 for details (explanation + graphs) on how Remote frecency compares to Local frecency for different
+     * combinations of visits count and age.
+     *
+     * @param now Base time in milliseconds for age calculation
+     * @return remote frecency SQL calculation
+     */
+    static public String getRemoteFrecencySQL(final long now) {
+        return getFrecencyCalculation(now, 1, 110, Combined.REMOTE_VISITS_COUNT, Combined.REMOTE_DATE_LAST_VISITED);
+    }
+
+    /**
+     * Local frecency SQL calculation. Note higher scale factor and squared visit count which achieve
+     * visits generated locally being much preferred over remote visits.
+     * See Bug 1265525 for details (explanation + comparison graphs).
+     *
+     * @param now Base time in milliseconds for age calculation
+     * @return local frecency SQL calculation
+     */
+    static public String getLocalFrecencySQL(final long now) {
+        String visitCountExpr = "(" + Combined.LOCAL_VISITS_COUNT + " + 2)";
+        visitCountExpr = visitCountExpr + " * " + visitCountExpr;
+
+        return getFrecencyCalculation(now, 2, 225, visitCountExpr, Combined.LOCAL_DATE_LAST_VISITED);
+    }
+
+    /**
+     * Our version of frecency is computed by scaling the number of visits by a multiplier
+     * that approximates Gaussian decay, based on how long ago the entry was last visited.
+     * Since we're limited by the math we can do with sqlite, we're calculating this
+     * approximation using the Cauchy distribution: multiplier = scale_const / (age^2 + scale_const).
+     * For example, with 15 as our scale parameter, we get a scale constant 15^2 = 225. Then:
+     * frecencyScore = numVisits * max(1, 100 * 225 / (age*age + 225)). (See bug 704977)
+     *
+     * @param now Base time in milliseconds for age calculation
+     * @param minFrecency Minimum allowed frecency value
+     * @param multiplier Scale constant
+     * @param visitCountExpr Expression which will produce a visit count
+     * @param lastVisitExpr Expression which will produce "last-visited" timestamp
+     * @return Frecency SQL calculation
+     */
+    static public String getFrecencyCalculation(final long now, final int minFrecency, final int multiplier, @NonNull  final String visitCountExpr, @NonNull final String lastVisitExpr) {
+        final long nowInMicroseconds = now * 1000;
+        final long microsecondsPerDay = 86400000000L;
+        final String ageExpr = "(" + nowInMicroseconds + " - " + lastVisitExpr + ") / " + microsecondsPerDay;
+
+        return visitCountExpr + " * MAX(" + minFrecency + ", 100 * " + multiplier + " / (" + ageExpr + " * " + ageExpr + " + " + multiplier + "))";
+    }
+
+    @RobocopTarget
+    public interface CommonColumns {
+        public static final String _ID = "_id";
+    }
+
+    @RobocopTarget
+    public interface DateSyncColumns {
+        public static final String DATE_CREATED = "created";
+        public static final String DATE_MODIFIED = "modified";
+    }
+
+    @RobocopTarget
+    public interface SyncColumns extends DateSyncColumns {
+        public static final String GUID = "guid";
+        public static final String IS_DELETED = "deleted";
+    }
+
+    @RobocopTarget
+    public interface URLColumns {
+        public static final String URL = "url";
+        public static final String TITLE = "title";
+    }
+
+    @RobocopTarget
+    public interface FaviconColumns {
+        public static final String FAVICON = "favicon";
+        public static final String FAVICON_ID = "favicon_id";
+        public static final String FAVICON_URL = "favicon_url";
+    }
+
+    @RobocopTarget
+    public interface HistoryColumns {
+        public static final String DATE_LAST_VISITED = "date";
+        public static final String VISITS = "visits";
+        // Aggregates used to speed up top sites and search frecency-powered queries
+        public static final String LOCAL_VISITS = "visits_local";
+        public static final String REMOTE_VISITS = "visits_remote";
+        public static final String LOCAL_DATE_LAST_VISITED = "date_local";
+        public static final String REMOTE_DATE_LAST_VISITED = "date_remote";
+    }
+
+    @RobocopTarget
+    public interface VisitsColumns {
+        public static final String HISTORY_GUID = "history_guid";
+        public static final String VISIT_TYPE = "visit_type";
+        public static final String DATE_VISITED = "date";
+        // Used to distinguish between visits that were generated locally vs those that came in from Sync.
+        // Since we don't track "origin clientID" for visits, this is the best we can do for now.
+        public static final String IS_LOCAL = "is_local";
+    }
+
+    public interface PageMetadataColumns {
+        public static final String HISTORY_GUID = "history_guid";
+        public static final String DATE_CREATED = "created";
+        public static final String HAS_IMAGE = "has_image";
+        public static final String JSON = "json";
+    }
+
+    public interface DeletedColumns {
+        public static final String ID = "id";
+        public static final String GUID = "guid";
+        public static final String TIME_DELETED = "timeDeleted";
+    }
+
+    @RobocopTarget
+    public static final class Favicons implements CommonColumns, DateSyncColumns {
+        private Favicons() {}
+
+        public static final String TABLE_NAME = "favicons";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "favicons");
+
+        public static final String URL = "url";
+        public static final String DATA = "data";
+        public static final String PAGE_URL = "page_url";
+    }
+
+    @RobocopTarget
+    public static final class Thumbnails implements CommonColumns {
+        private Thumbnails() {}
+
+        public static final String TABLE_NAME = "thumbnails";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "thumbnails");
+
+        public static final String URL = "url";
+        public static final String DATA = "data";
+    }
+
+    public static final class Profiles {
+        private Profiles() {}
+        public static final String NAME = "name";
+        public static final String PATH = "path";
+    }
+
+    @RobocopTarget
+    public static final class Bookmarks implements CommonColumns, URLColumns, FaviconColumns, SyncColumns {
+        private Bookmarks() {}
+
+        public static final String TABLE_NAME = "bookmarks";
+
+        public static final String VIEW_WITH_FAVICONS = "bookmarks_with_favicons";
+
+        public static final String VIEW_WITH_ANNOTATIONS = "bookmarks_with_annotations";
+
+        public static final int FIXED_ROOT_ID = 0;
+        public static final int FAKE_DESKTOP_FOLDER_ID = -1;
+        public static final int FIXED_READING_LIST_ID = -2;
+        public static final int FIXED_PINNED_LIST_ID = -3;
+        public static final int FIXED_SCREENSHOT_FOLDER_ID = -4;
+        public static final int FAKE_READINGLIST_SMARTFOLDER_ID = -5;
+
+        /**
+         * This ID and the following negative IDs are reserved for bookmarks from Android's partner
+         * bookmark provider.
+         */
+        public static final long FAKE_PARTNER_BOOKMARKS_START = -1000;
+
+        public static final String MOBILE_FOLDER_GUID = "mobile";
+        public static final String PLACES_FOLDER_GUID = "places";
+        public static final String MENU_FOLDER_GUID = "menu";
+        public static final String TAGS_FOLDER_GUID = "tags";
+        public static final String TOOLBAR_FOLDER_GUID = "toolbar";
+        public static final String UNFILED_FOLDER_GUID = "unfiled";
+        public static final String FAKE_DESKTOP_FOLDER_GUID = "desktop";
+        public static final String PINNED_FOLDER_GUID = "pinned";
+        public static final String SCREENSHOT_FOLDER_GUID = "screenshots";
+        public static final String FAKE_READINGLIST_SMARTFOLDER_GUID = "readinglist";
+
+        public static final int TYPE_FOLDER = 0;
+        public static final int TYPE_BOOKMARK = 1;
+        public static final int TYPE_SEPARATOR = 2;
+        public static final int TYPE_LIVEMARK = 3;
+        public static final int TYPE_QUERY = 4;
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "bookmarks");
+        public static final Uri PARENTS_CONTENT_URI = Uri.withAppendedPath(CONTENT_URI, "parents");
+        // Hacky API for bulk-updating positions. Bug 728783.
+        public static final Uri POSITIONS_CONTENT_URI = Uri.withAppendedPath(CONTENT_URI, "positions");
+        public static final long DEFAULT_POSITION = Long.MIN_VALUE;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/bookmark";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/bookmark";
+        public static final String TYPE = "type";
+        public static final String PARENT = "parent";
+        public static final String POSITION = "position";
+        public static final String TAGS = "tags";
+        public static final String DESCRIPTION = "description";
+        public static final String KEYWORD = "keyword";
+
+        public static final String ANNOTATION_KEY = "annotation_key";
+        public static final String ANNOTATION_VALUE = "annotation_value";
+    }
+
+    @RobocopTarget
+    public static final class History implements CommonColumns, URLColumns, HistoryColumns, FaviconColumns, SyncColumns {
+        private History() {}
+
+        public static final String TABLE_NAME = "history";
+
+        public static final String VIEW_WITH_FAVICONS = "history_with_favicons";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "history");
+        public static final Uri CONTENT_OLD_URI = Uri.withAppendedPath(AUTHORITY_URI, "history/old");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/browser-history";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/browser-history";
+    }
+
+    @RobocopTarget
+    public static final class Visits implements CommonColumns, VisitsColumns {
+        private Visits() {}
+
+        public static final String TABLE_NAME = "visits";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "visits");
+
+        public static final int VISIT_IS_LOCAL = 1;
+        public static final int VISIT_IS_REMOTE = 0;
+    }
+
+    // Combined bookmarks and history
+    @RobocopTarget
+    public static final class Combined implements CommonColumns, URLColumns, HistoryColumns, FaviconColumns  {
+        private Combined() {}
+
+        public static final String VIEW_NAME = "combined";
+
+        public static final String VIEW_WITH_FAVICONS = "combined_with_favicons";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "combined");
+
+        public static final String BOOKMARK_ID = "bookmark_id";
+        public static final String HISTORY_ID = "history_id";
+
+        public static final String REMOTE_VISITS_COUNT = "remoteVisitCount";
+        public static final String REMOTE_DATE_LAST_VISITED = "remoteDateLastVisited";
+
+        public static final String LOCAL_VISITS_COUNT = "localVisitCount";
+        public static final String LOCAL_DATE_LAST_VISITED = "localDateLastVisited";
+    }
+
+    public static final class Schema {
+        private Schema() {}
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "schema");
+
+        public static final String VERSION = "version";
+    }
+
+    public static final class Passwords {
+        private Passwords() {}
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(PASSWORDS_AUTHORITY_URI, "passwords");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/passwords";
+
+        public static final String ID = "id";
+        public static final String HOSTNAME = "hostname";
+        public static final String HTTP_REALM = "httpRealm";
+        public static final String FORM_SUBMIT_URL = "formSubmitURL";
+        public static final String USERNAME_FIELD = "usernameField";
+        public static final String PASSWORD_FIELD = "passwordField";
+        public static final String ENCRYPTED_USERNAME = "encryptedUsername";
+        public static final String ENCRYPTED_PASSWORD = "encryptedPassword";
+        public static final String ENC_TYPE = "encType";
+        public static final String TIME_CREATED = "timeCreated";
+        public static final String TIME_LAST_USED = "timeLastUsed";
+        public static final String TIME_PASSWORD_CHANGED = "timePasswordChanged";
+        public static final String TIMES_USED = "timesUsed";
+        public static final String GUID = "guid";
+
+        // This needs to be kept in sync with the types defined in toolkit/components/passwordmgr/nsILoginManagerCrypto.idl#45
+        public static final int ENCTYPE_SDR = 1;
+    }
+
+    public static final class DeletedPasswords implements DeletedColumns {
+        private DeletedPasswords() {}
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/deleted-passwords";
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(PASSWORDS_AUTHORITY_URI, "deleted-passwords");
+    }
+
+    @RobocopTarget
+    public static final class GeckoDisabledHosts {
+        private GeckoDisabledHosts() {}
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/disabled-hosts";
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(PASSWORDS_AUTHORITY_URI, "disabled-hosts");
+
+        public static final String HOSTNAME = "hostname";
+    }
+
+    public static final class FormHistory {
+        private FormHistory() {}
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(FORM_HISTORY_AUTHORITY_URI, "formhistory");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/formhistory";
+
+        public static final String ID = "id";
+        public static final String FIELD_NAME = "fieldname";
+        public static final String VALUE = "value";
+        public static final String TIMES_USED = "timesUsed";
+        public static final String FIRST_USED = "firstUsed";
+        public static final String LAST_USED = "lastUsed";
+        public static final String GUID = "guid";
+    }
+
+    public static final class DeletedFormHistory implements DeletedColumns {
+        private DeletedFormHistory() {}
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(FORM_HISTORY_AUTHORITY_URI, "deleted-formhistory");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/deleted-formhistory";
+    }
+
+    @RobocopTarget
+    public static final class Tabs implements CommonColumns {
+        private Tabs() {}
+        public static final String TABLE_NAME = "tabs";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(TABS_AUTHORITY_URI, "tabs");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/tab";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/tab";
+
+        // Title of the tab.
+        public static final String TITLE = "title";
+
+        // Topmost URL from the history array. Allows processing of this tab without
+        // parsing that array.
+        public static final String URL = "url";
+
+        // Sync-assigned GUID for client device. NULL for local tabs.
+        public static final String CLIENT_GUID = "client_guid";
+
+        // JSON-encoded array of history URL strings, from most recent to least recent.
+        public static final String HISTORY = "history";
+
+        // Favicon URL for the tab's topmost history entry.
+        public static final String FAVICON = "favicon";
+
+        // Last used time of the tab.
+        public static final String LAST_USED = "last_used";
+
+        // Position of the tab. 0 represents foreground.
+        public static final String POSITION = "position";
+    }
+
+    public static final class Clients implements CommonColumns {
+        private Clients() {}
+        public static final Uri CONTENT_RECENCY_URI = Uri.withAppendedPath(TABS_AUTHORITY_URI, "clients_recency");
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(TABS_AUTHORITY_URI, "clients");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/client";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/client";
+
+        // Client-provided name string. Could conceivably be null.
+        public static final String NAME = "name";
+
+        // Sync-assigned GUID for client device. NULL for local tabs.
+        public static final String GUID = "guid";
+
+        // Last modified time for the client's tab record. For remote records, a server
+        // timestamp provided by Sync during insertion.
+        public static final String LAST_MODIFIED = "last_modified";
+
+        public static final String DEVICE_TYPE = "device_type";
+    }
+
+    // Data storage for dynamic panels on about:home
+    @RobocopTarget
+    public static final class HomeItems implements CommonColumns {
+        private HomeItems() {}
+        public static final Uri CONTENT_FAKE_URI = Uri.withAppendedPath(HOME_AUTHORITY_URI, "items/fake");
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(HOME_AUTHORITY_URI, "items");
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/homeitem";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/homeitem";
+
+        public static final String DATASET_ID = "dataset_id";
+        public static final String URL = "url";
+        public static final String TITLE = "title";
+        public static final String DESCRIPTION = "description";
+        public static final String IMAGE_URL = "image_url";
+        public static final String BACKGROUND_COLOR = "background_color";
+        public static final String BACKGROUND_URL = "background_url";
+        public static final String CREATED = "created";
+        public static final String FILTER = "filter";
+
+        public static final String[] DEFAULT_PROJECTION =
+            new String[] { _ID, DATASET_ID, URL, TITLE, DESCRIPTION, IMAGE_URL, BACKGROUND_COLOR, BACKGROUND_URL, FILTER };
+    }
+
+    @RobocopTarget
+    public static final class ReadingListItems implements CommonColumns, URLColumns {
+        public static final String EXCERPT = "excerpt";
+        public static final String CLIENT_LAST_MODIFIED = "client_last_modified";
+        public static final String GUID = "guid";
+        public static final String SERVER_LAST_MODIFIED = "last_modified";
+        public static final String SERVER_STORED_ON = "stored_on";
+        public static final String ADDED_ON = "added_on";
+        public static final String MARKED_READ_ON = "marked_read_on";
+        public static final String IS_DELETED = "is_deleted";
+        public static final String IS_ARCHIVED = "is_archived";
+        public static final String IS_UNREAD = "is_unread";
+        public static final String IS_ARTICLE = "is_article";
+        public static final String IS_FAVORITE = "is_favorite";
+        public static final String RESOLVED_URL = "resolved_url";
+        public static final String RESOLVED_TITLE = "resolved_title";
+        public static final String ADDED_BY = "added_by";
+        public static final String MARKED_READ_BY = "marked_read_by";
+        public static final String WORD_COUNT = "word_count";
+        public static final String READ_POSITION = "read_position";
+        public static final String CONTENT_STATUS = "content_status";
+
+        public static final String SYNC_STATUS = "sync_status";
+        public static final String SYNC_CHANGE_FLAGS = "sync_change_flags";
+
+        private ReadingListItems() {}
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(READING_LIST_AUTHORITY_URI, "items");
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/readinglistitem";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/readinglistitem";
+
+        // CONTENT_STATUS represents the result of an attempt to fetch content for the reading list item.
+        public static final int STATUS_UNFETCHED = 0;
+        public static final int STATUS_FETCH_FAILED_TEMPORARY = 1;
+        public static final int STATUS_FETCH_FAILED_PERMANENT = 2;
+        public static final int STATUS_FETCH_FAILED_UNSUPPORTED_FORMAT = 3;
+        public static final int STATUS_FETCHED_ARTICLE = 4;
+
+        // See https://github.com/mozilla-services/readinglist/wiki/Client-phases for how this is expected to work.
+        //
+        // If an item is SYNCED, it doesn't need to be uploaded.
+        //
+        // If its status is NEW, the entire record should be uploaded.
+        //
+        // If DELETED, the record should be deleted. A record can only move into this state from SYNCED; NEW records
+        // are deleted immediately.
+        //
+
+        public static final int SYNC_STATUS_SYNCED = 0;
+        public static final int SYNC_STATUS_NEW = 1;                      // Upload everything.
+        public static final int SYNC_STATUS_DELETED = 2;                  // Delete the record from the server.
+        public static final int SYNC_STATUS_MODIFIED = 3;                 // Consult SYNC_CHANGE_FLAGS.
+
+        // SYNC_CHANGE_FLAG represents the sets of fields that need to be uploaded.
+        // If its status is only UNREAD_CHANGED (and maybe FAVORITE_CHANGED?), then it can easily be uploaded
+        // in a fire-and-forget manner. This change can never conflict.
+        //
+        // If its status is RESOLVED, then one or more of the content-oriented fields has changed, and a full
+        // upload of those fields should occur. These can result in conflicts.
+        //
+        // Note that these are flags; they should be considered together when deciding on a course of action.
+        //
+        // These flags are meaningless for records in any state other than SYNCED. They can be safely altered in
+        // other states (to avoid having to query to pre-fill a ContentValues), but should be ignored.
+        public static final int SYNC_CHANGE_NONE = 0;
+        public static final int SYNC_CHANGE_UNREAD_CHANGED   = 1 << 0;    // => marked_read_{on,by}, is_unread
+        public static final int SYNC_CHANGE_FAVORITE_CHANGED = 1 << 1;    // => is_favorite
+        public static final int SYNC_CHANGE_RESOLVED = 1 << 2;            // => is_article, resolved_{url,title}, excerpt, word_count
+
+
+        public static final String DEFAULT_SORT_ORDER = CLIENT_LAST_MODIFIED + " DESC";
+        public static final String[] DEFAULT_PROJECTION = new String[] { _ID, URL, TITLE, EXCERPT, WORD_COUNT, IS_UNREAD };
+
+        // Minimum fields required to create a reading list item.
+        public static final String[] REQUIRED_FIELDS = { ReadingListItems.URL, ReadingListItems.TITLE };
+
+        // All fields that might be mapped from the DB into a record object.
+        public static final String[] ALL_FIELDS = {
+                CommonColumns._ID,
+                URLColumns.URL,
+                URLColumns.TITLE,
+                EXCERPT,
+                CLIENT_LAST_MODIFIED,
+                GUID,
+                SERVER_LAST_MODIFIED,
+                SERVER_STORED_ON,
+                ADDED_ON,
+                MARKED_READ_ON,
+                IS_DELETED,
+                IS_ARCHIVED,
+                IS_UNREAD,
+                IS_ARTICLE,
+                IS_FAVORITE,
+                RESOLVED_URL,
+                RESOLVED_TITLE,
+                ADDED_BY,
+                MARKED_READ_BY,
+                WORD_COUNT,
+                READ_POSITION,
+                CONTENT_STATUS,
+
+                SYNC_STATUS,
+                SYNC_CHANGE_FLAGS,
+        };
+
+        public static final String TABLE_NAME = "reading_list";
+    }
+
+    @RobocopTarget
+    public static final class TopSites implements CommonColumns, URLColumns {
+        private TopSites() {}
+
+        public static final int TYPE_BLANK = 0;
+        public static final int TYPE_TOP = 1;
+        public static final int TYPE_PINNED = 2;
+        public static final int TYPE_SUGGESTED = 3;
+
+        public static final String BOOKMARK_ID = "bookmark_id";
+        public static final String HISTORY_ID = "history_id";
+        public static final String TYPE = "type";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "topsites");
+    }
+
+    public static final class Highlights {
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "highlights");
+
+        public static final String DATE = "date";
+    }
+
+    @RobocopTarget
+    public static final class SearchHistory implements CommonColumns, HistoryColumns {
+        private SearchHistory() {}
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/searchhistory";
+        public static final String QUERY = "query";
+        public static final String DATE = "date";
+        public static final String TABLE_NAME = "searchhistory";
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(SEARCH_HISTORY_AUTHORITY_URI, "searchhistory");
+    }
+
+    @RobocopTarget
+    public static final class SuggestedSites implements CommonColumns, URLColumns {
+        private SuggestedSites() {}
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "suggestedsites");
+    }
+
+    public static final class ActivityStreamBlocklist implements CommonColumns {
+        private ActivityStreamBlocklist() {}
+
+        public static final String TABLE_NAME = "activity_stream_blocklist";
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, TABLE_NAME);
+
+        public static final String URL = "url";
+        public static final String CREATED = "created";
+    }
+
+    @RobocopTarget
+    public static final class UrlAnnotations implements CommonColumns, DateSyncColumns {
+        private UrlAnnotations() {}
+
+        public static final String TABLE_NAME = "urlannotations";
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, TABLE_NAME);
+
+        public static final String URL = "url";
+        public static final String KEY = "key";
+        public static final String VALUE = "value";
+        public static final String SYNC_STATUS = "sync_status";
+
+        public enum Key {
+            // We use a parameter, rather than name(), as defensive coding: we can't let the
+            // enum name change because we've already stored values into the DB.
+            SCREENSHOT ("screenshot"),
+
+            /**
+             * This key maps URLs to its feeds.
+             *
+             * Key:   feed
+             * Value: URL of feed
+             */
+            FEED("feed"),
+
+            /**
+             * This key maps URLs of feeds to an object describing the feed.
+             *
+             * Key:   feed_subscription
+             * Value: JSON object describing feed
+             */
+            FEED_SUBSCRIPTION("feed_subscription"),
+
+            /**
+             * Indicates that this URL (if stored as a bookmark) should be opened into reader view.
+             *
+             * Key:   reader_view
+             * Value: String "true" to indicate that we would like to open into reader view.
+             */
+            READER_VIEW("reader_view"),
+
+            /**
+             * Indicator that the user interacted with the URL in regards to home screen shortcuts.
+             *
+             * Key:   home_screen_shortcut
+             * Value: True: User created an home screen shortcut for this URL
+             *        False: User declined to create a shortcut for this URL
+             */
+            HOME_SCREEN_SHORTCUT("home_screen_shortcut");
+
+            private final String dbValue;
+
+            Key(final String dbValue) { this.dbValue = dbValue; }
+            public String getDbValue() { return dbValue; }
+        }
+
+        public enum SyncStatus {
+            // We use a parameter, rather than ordinal(), as defensive coding: we can't let the
+            // ordinal values change because we've already stored values into the DB.
+            NEW (0);
+
+            // Value stored into the database for this column.
+            private final int dbValue;
+
+            SyncStatus(final int dbValue) {
+                this.dbValue = dbValue;
+            }
+
+            public int getDBValue() { return dbValue; }
+        }
+
+        /**
+         * Value used to indicate that a reader view item is saved. We use the
+         */
+        public static final String READER_VIEW_SAVED_VALUE = "true";
+    }
+
+    public static final class Numbers {
+        private Numbers() {}
+
+        public static final String TABLE_NAME = "numbers";
+
+        public static final String POSITION = "position";
+
+        public static final int MAX_VALUE = 50;
+    }
+
+    @RobocopTarget
+    public static final class Logins implements CommonColumns {
+        private Logins() {}
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(LOGINS_AUTHORITY_URI, "logins");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/logins";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/logins";
+        public static final String TABLE_LOGINS = "logins";
+
+        public static final String HOSTNAME = "hostname";
+        public static final String HTTP_REALM = "httpRealm";
+        public static final String FORM_SUBMIT_URL = "formSubmitURL";
+        public static final String USERNAME_FIELD = "usernameField";
+        public static final String PASSWORD_FIELD = "passwordField";
+        public static final String ENCRYPTED_USERNAME = "encryptedUsername";
+        public static final String ENCRYPTED_PASSWORD = "encryptedPassword";
+        public static final String ENC_TYPE = "encType";
+        public static final String TIME_CREATED = "timeCreated";
+        public static final String TIME_LAST_USED = "timeLastUsed";
+        public static final String TIME_PASSWORD_CHANGED = "timePasswordChanged";
+        public static final String TIMES_USED = "timesUsed";
+        public static final String GUID = "guid";
+    }
+
+    @RobocopTarget
+    public static final class DeletedLogins implements CommonColumns {
+        private DeletedLogins() {}
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(LOGINS_AUTHORITY_URI, "deleted-logins");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/deleted-logins";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/deleted-logins";
+        public static final String TABLE_DELETED_LOGINS = "deleted_logins";
+
+        public static final String GUID = "guid";
+        public static final String TIME_DELETED = "timeDeleted";
+    }
+
+    @RobocopTarget
+    public static final class LoginsDisabledHosts implements CommonColumns {
+        private LoginsDisabledHosts() {}
+
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(LOGINS_AUTHORITY_URI, "logins-disabled-hosts");
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/logins-disabled-hosts";
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/logins-disabled-hosts";
+        public static final String TABLE_DISABLED_HOSTS = "logins_disabled_hosts";
+
+        public static final String HOSTNAME = "hostname";
+    }
+
+    @RobocopTarget
+    public static final class PageMetadata implements CommonColumns, PageMetadataColumns {
+        private PageMetadata() {}
+
+        public static final String TABLE_NAME = "page_metadata";
+        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "page_metadata");
+    }
+
+    // We refer to the service by name to decouple services from the rest of the code base.
+    public static final String TAB_RECEIVED_SERVICE_CLASS_NAME = "org.mozilla.gecko.tabqueue.TabReceivedService";
+
+    public static final String SKIP_TAB_QUEUE_FLAG = "skip_tab_queue";
+
+    public static final String EXTRA_CLIENT_GUID = "org.mozilla.gecko.extra.CLIENT_ID";
+}

mobile/android/base/java/org/mozilla/gecko/db/BrowserDB.java

@@ -0,0 +1,205 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.io.File;
+import java.util.Collection;
+import java.util.EnumSet;
+import java.util.List;
+
+import org.mozilla.gecko.GeckoProfile;
+import org.mozilla.gecko.annotation.RobocopTarget;
+import org.mozilla.gecko.db.BrowserContract.ExpirePriority;
+import org.mozilla.gecko.distribution.Distribution;
+import org.mozilla.gecko.icons.decoders.LoadFaviconResult;
+
+import android.content.ContentProviderClient;
+import android.content.ContentProviderOperation;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.database.ContentObserver;
+import android.database.Cursor;
+import android.graphics.drawable.BitmapDrawable;
+import android.support.v4.content.CursorLoader;
+
+/**
+ * Interface for interactions with all databases. If you want an instance
+ * that implements this, you should go through GeckoProfile. E.g.,
+ * <code>BrowserDB.from(context)</code>.
+ */
+public abstract class BrowserDB {
+    public static enum FilterFlags {
+        EXCLUDE_PINNED_SITES
+    }
+
+    public abstract Searches getSearches();
+    public abstract TabsAccessor getTabsAccessor();
+    public abstract URLMetadata getURLMetadata();
+    @RobocopTarget public abstract UrlAnnotations getUrlAnnotations();
+
+    /**
+     * Add default bookmarks to the database.
+     * Takes an offset; returns a new offset.
+     */
+    public abstract int addDefaultBookmarks(Context context, ContentResolver cr, int offset);
+
+    /**
+     * Add bookmarks from the provided distribution.
+     * Takes an offset; returns a new offset.
+     */
+    public abstract int addDistributionBookmarks(ContentResolver cr, Distribution distribution, int offset);
+
+    /**
+     * Invalidate cached data.
+     */
+    public abstract void invalidate();
+
+    public abstract int getCount(ContentResolver cr, String database);
+
+    /**
+     * @return a cursor representing the contents of the DB filtered according to the arguments.
+     * Can return <code>null</code>. <code>CursorLoader</code> will handle this correctly.
+     */
+    public abstract Cursor filter(ContentResolver cr, CharSequence constraint,
+                                  int limit, EnumSet<BrowserDB.FilterFlags> flags);
+
+    /**
+     * @return a cursor over top sites (high-ranking bookmarks and history).
+     * Can return <code>null</code>.
+     * Returns no more than <code>limit</code> results.
+     * Suggested sites will be limited to being within the first <code>suggestedRangeLimit</code> results.
+     */
+    public abstract Cursor getTopSites(ContentResolver cr, int suggestedRangeLimit, int limit);
+
+    public abstract CursorLoader getActivityStreamTopSites(Context context, int limit);
+
+    public abstract void updateVisitedHistory(ContentResolver cr, String uri);
+
+    public abstract void updateHistoryTitle(ContentResolver cr, String uri, String title);
+
+    /**
+     * Can return <code>null</code>.
+     */
+    public abstract Cursor getAllVisitedHistory(ContentResolver cr);
+
+    /**
+     * Can return <code>null</code>.
+     */
+    public abstract Cursor getRecentHistory(ContentResolver cr, int limit);
+
+    public abstract Cursor getHistoryForURL(ContentResolver cr, String uri);
+
+    public abstract Cursor getRecentHistoryBetweenTime(ContentResolver cr, int historyLimit, long start, long end);
+
+    public abstract long getPrePathLastVisitedTimeMilliseconds(ContentResolver cr, String prePath);
+
+    public abstract void expireHistory(ContentResolver cr, ExpirePriority priority);
+
+    public abstract void removeHistoryEntry(ContentResolver cr, String url);
+
+    public abstract void clearHistory(ContentResolver cr, boolean clearSearchHistory);
+
+
+    public abstract String getUrlForKeyword(ContentResolver cr, String keyword);
+
+    public abstract boolean isBookmark(ContentResolver cr, String uri);
+    public abstract boolean addBookmark(ContentResolver cr, String title, String uri);
+    public abstract Cursor getBookmarkForUrl(ContentResolver cr, String url);
+    public abstract Cursor getBookmarksForPartialUrl(ContentResolver cr, String partialUrl);
+    public abstract void removeBookmarksWithURL(ContentResolver cr, String uri);
+    public abstract void registerBookmarkObserver(ContentResolver cr, ContentObserver observer);
+    public abstract void updateBookmark(ContentResolver cr, int id, String uri, String title, String keyword);
+    public abstract boolean hasBookmarkWithGuid(ContentResolver cr, String guid);
+
+    public abstract boolean insertPageMetadata(ContentProviderClient contentProviderClient, String pageUrl, boolean hasImage, String metadataJSON);
+    public abstract int deletePageMetadata(ContentProviderClient contentProviderClient, String pageUrl);
+    /**
+     * Can return <code>null</code>.
+     */
+    public abstract Cursor getBookmarksInFolder(ContentResolver cr, long folderId);
+
+    public abstract int getBookmarkCountForFolder(ContentResolver cr, long folderId);
+
+    /**
+     * Get the favicon from the database, if any, associated with the given favicon URL. (That is,
+     * the URL of the actual favicon image, not the URL of the page with which the favicon is associated.)
+     * @param cr The ContentResolver to use.
+     * @param faviconURL The URL of the favicon to fetch from the database.
+     * @return The decoded Bitmap from the database, if any. null if none is stored.
+     */
+    public abstract LoadFaviconResult getFaviconForUrl(Context context, ContentResolver cr, String faviconURL);
+
+    /**
+     * Try to find a usable favicon URL in the history or bookmarks table.
+     */
+    public abstract String getFaviconURLFromPageURL(ContentResolver cr, String uri);
+
+    public abstract byte[] getThumbnailForUrl(ContentResolver cr, String uri);
+    public abstract void updateThumbnailForUrl(ContentResolver cr, String uri, BitmapDrawable thumbnail);
+
+    /**
+     * Query for non-null thumbnails matching the provided <code>urls</code>.
+     * The returned cursor will have no more than, but possibly fewer than,
+     * the requested number of thumbnails.
+     *
+     * Returns null if the provided list of URLs is empty or null.
+     */
+    public abstract Cursor getThumbnailsForUrls(ContentResolver cr,
+            List<String> urls);
+
+    public abstract void removeThumbnails(ContentResolver cr);
+
+    // Utility function for updating existing history using batch operations
+    public abstract void updateHistoryInBatch(ContentResolver cr,
+            Collection<ContentProviderOperation> operations, String url,
+            String title, long date, int visits);
+
+    public abstract void updateBookmarkInBatch(ContentResolver cr,
+            Collection<ContentProviderOperation> operations, String url,
+            String title, String guid, long parent, long added, long modified,
+            long position, String keyword, int type);
+
+    public abstract void pinSite(ContentResolver cr, String url, String title, int position);
+    public abstract void unpinSite(ContentResolver cr, int position);
+
+    public abstract boolean hideSuggestedSite(String url);
+    public abstract void setSuggestedSites(SuggestedSites suggestedSites);
+    public abstract SuggestedSites getSuggestedSites();
+    public abstract boolean hasSuggestedImageUrl(String url);
+    public abstract String getSuggestedImageUrlForUrl(String url);
+    public abstract int getSuggestedBackgroundColorForUrl(String url);
+
+    /**
+     * Obtain a set of links for highlights from bookmarks and history.
+     *
+     * @param context The context to load the cursor.
+     * @param limit Maximum number of results to return.
+     */
+    public abstract CursorLoader getHighlights(Context context, int limit);
+
+    /**
+     * Block a page from the highlights list.
+     *
+     * @param url The page URL. Only pages exactly matching this URL will be blocked.
+     */
+    public abstract void blockActivityStreamSite(ContentResolver cr, String url);
+
+    public static BrowserDB from(final Context context) {
+        return from(GeckoProfile.get(context));
+    }
+
+    public static BrowserDB from(final GeckoProfile profile) {
+        synchronized (profile.getLock()) {
+            BrowserDB db = (BrowserDB) profile.getData();
+            if (db != null) {
+                return db;
+            }
+
+            db = new LocalBrowserDB(profile.getName());
+            profile.setData(db);
+            return db;
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/DBUtils.java

@@ -0,0 +1,450 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.annotation.TargetApi;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteStatement;
+import android.os.Build;
+import org.mozilla.gecko.AppConstants;
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.GeckoProfile;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+import org.mozilla.gecko.annotation.RobocopTarget;
+import org.mozilla.gecko.Telemetry;
+
+import java.util.Map;
+
+public class DBUtils {
+    private static final String LOGTAG = "GeckoDBUtils";
+
+    public static final int SQLITE_MAX_VARIABLE_NUMBER = 999;
+
+    public static final String qualifyColumn(String table, String column) {
+        return table + "." + column;
+    }
+
+    // This is available in Android >= 11. Implemented locally to be
+    // compatible with older versions.
+    public static String concatenateWhere(String a, String b) {
+        if (TextUtils.isEmpty(a)) {
+            return b;
+        }
+
+        if (TextUtils.isEmpty(b)) {
+            return a;
+        }
+
+        return "(" + a + ") AND (" + b + ")";
+    }
+
+    // This is available in Android >= 11. Implemented locally to be
+    // compatible with older versions.
+    public static String[] appendSelectionArgs(String[] originalValues, String[] newValues) {
+        if (originalValues == null || originalValues.length == 0) {
+            return newValues;
+        }
+
+        if (newValues == null || newValues.length == 0) {
+            return originalValues;
+        }
+
+        String[] result = new String[originalValues.length + newValues.length];
+        System.arraycopy(originalValues, 0, result, 0, originalValues.length);
+        System.arraycopy(newValues, 0, result, originalValues.length, newValues.length);
+
+        return result;
+    }
+
+    /**
+     * Concatenate multiple lists of selection arguments. <code>values</code> may be <code>null</code>.
+     */
+    public static String[] concatenateSelectionArgs(String[]... values) {
+        // Since we're most likely to be concatenating a few arrays of many values, it is most
+        // efficient to iterate over the arrays once to obtain their lengths, allowing us to create one target array
+        // (as opposed to copying arrays on every iteration, which would result in many more copies).
+        int totalLength = 0;
+        for (String[] v : values) {
+            if (v != null) {
+                totalLength += v.length;
+            }
+        }
+
+        String[] result = new String[totalLength];
+
+        int position = 0;
+        for (String[] v: values) {
+            if (v != null) {
+                int currentLength = v.length;
+                System.arraycopy(v, 0, result, position, currentLength);
+                position += currentLength;
+            }
+        }
+
+        return result;
+    }
+
+    public static void replaceKey(ContentValues aValues, String aOriginalKey,
+                                  String aNewKey, String aDefault) {
+        String value = aDefault;
+        if (aOriginalKey != null && aValues.containsKey(aOriginalKey)) {
+            value = aValues.get(aOriginalKey).toString();
+            aValues.remove(aOriginalKey);
+        }
+
+        if (!aValues.containsKey(aNewKey)) {
+            aValues.put(aNewKey, value);
+        }
+    }
+
+    private static String HISTOGRAM_DATABASE_LOCKED = "DATABASE_LOCKED_EXCEPTION";
+    private static String HISTOGRAM_DATABASE_UNLOCKED = "DATABASE_SUCCESSFUL_UNLOCK";
+    public static void ensureDatabaseIsNotLocked(SQLiteOpenHelper dbHelper, String databasePath) {
+        final int maxAttempts = 5;
+        int attempt = 0;
+        SQLiteDatabase db = null;
+        for (; attempt < maxAttempts; attempt++) {
+            try {
+                // Try a simple test and exit the loop.
+                db = dbHelper.getWritableDatabase();
+                break;
+            } catch (Exception e) {
+                // We assume that this is a android.database.sqlite.SQLiteDatabaseLockedException.
+                // That class is only available on API 11+.
+                Telemetry.addToHistogram(HISTOGRAM_DATABASE_LOCKED, attempt);
+
+                // Things could get very bad if we don't find a way to unlock the DB.
+                Log.d(LOGTAG, "Database is locked, trying to kill any zombie processes: " + databasePath);
+                GeckoAppShell.killAnyZombies();
+                try {
+                    Thread.sleep(attempt * 100);
+                } catch (InterruptedException ie) {
+                }
+            }
+        }
+
+        if (db == null) {
+            Log.w(LOGTAG, "Failed to unlock database.");
+            GeckoAppShell.listOfOpenFiles();
+            return;
+        }
+
+        // If we needed to retry, but we succeeded, report that in telemetry.
+        // Failures are indicated by a lower frequency of UNLOCKED than LOCKED.
+        if (attempt > 1) {
+            Telemetry.addToHistogram(HISTOGRAM_DATABASE_UNLOCKED, attempt - 1);
+        }
+    }
+
+    /**
+     * Copies a table <b>between</b> database files.
+     *
+     * This method assumes that the source table and destination table already exist in the
+     * source and destination databases, respectively.
+     *
+     * The table is copied row-by-row in a single transaction.
+     *
+     * @param source The source database that the table will be copied from.
+     * @param sourceTableName The name of the source table.
+     * @param destination The destination database that the table will be copied to.
+     * @param destinationTableName The name of the destination table.
+     * @return true if all rows were copied; false otherwise.
+     */
+    public static boolean copyTable(SQLiteDatabase source, String sourceTableName,
+                                    SQLiteDatabase destination, String destinationTableName) {
+        Cursor cursor = null;
+        try {
+            destination.beginTransaction();
+
+            cursor = source.query(sourceTableName, null, null, null, null, null, null);
+            Log.d(LOGTAG, "Trying to copy " + cursor.getCount() + " rows from " + sourceTableName + " to " + destinationTableName);
+
+            final ContentValues contentValues = new ContentValues();
+            while (cursor.moveToNext()) {
+                contentValues.clear();
+                DatabaseUtils.cursorRowToContentValues(cursor, contentValues);
+                destination.insert(destinationTableName, null, contentValues);
+            }
+
+            destination.setTransactionSuccessful();
+            Log.d(LOGTAG, "Successfully copied " + cursor.getCount() + " rows from " + sourceTableName + " to " + destinationTableName);
+            return true;
+        } catch (Exception e) {
+            Log.w(LOGTAG, "Got exception copying rows from " + sourceTableName + " to " + destinationTableName + "; ignoring.", e);
+            return false;
+        } finally {
+            destination.endTransaction();
+            if (cursor != null) {
+                cursor.close();
+            }
+        }
+    }
+
+    /**
+     * Verifies that 0-byte arrays aren't added as favicon or thumbnail data.
+     * @param values        ContentValues of query
+     * @param columnName    Name of data column to verify
+     */
+    public static void stripEmptyByteArray(ContentValues values, String columnName) {
+        if (values.containsKey(columnName)) {
+            byte[] data = values.getAsByteArray(columnName);
+            if (data == null || data.length == 0) {
+                Log.w(LOGTAG, "Tried to insert an empty or non-byte-array image. Ignoring.");
+                values.putNull(columnName);
+            }
+        }
+    }
+
+    /**
+     * Builds a selection string that searches for a list of arguments in a particular column.
+     * For example URL in (?,?,?). Callers should pass the actual arguments into their query
+     * as selection args.
+     * @para columnName   The column to search in
+     * @para size         The number of arguments to search for
+     */
+    public static String computeSQLInClause(int items, String field) {
+        final StringBuilder builder = new StringBuilder(field);
+        builder.append(" IN (");
+        int i = 0;
+        for (; i < items - 1; ++i) {
+            builder.append("?, ");
+        }
+        if (i < items) {
+            builder.append("?");
+        }
+        builder.append(")");
+        return builder.toString();
+    }
+
+    /**
+     * Turn a single-column cursor of longs into a single SQL "IN" clause.
+     * We can do this without using selection arguments because Long isn't
+     * vulnerable to injection.
+     */
+    public static String computeSQLInClauseFromLongs(final Cursor cursor, String field) {
+        final StringBuilder builder = new StringBuilder(field);
+        builder.append(" IN (");
+        final int commaLimit = cursor.getCount() - 1;
+        int i = 0;
+        while (cursor.moveToNext()) {
+            builder.append(cursor.getLong(0));
+            if (i++ < commaLimit) {
+                builder.append(", ");
+            }
+        }
+        builder.append(")");
+        return builder.toString();
+    }
+
+    public static Uri appendProfile(final String profile, final Uri uri) {
+        return uri.buildUpon().appendQueryParameter(BrowserContract.PARAM_PROFILE, profile).build();
+    }
+
+    public static Uri appendProfileWithDefault(final String profile, final Uri uri) {
+        if (profile == null) {
+            return appendProfile(GeckoProfile.DEFAULT_PROFILE, uri);
+        }
+        return appendProfile(profile, uri);
+    }
+
+    /**
+     * Use the following when no conflict action is specified.
+     */
+    private static final int CONFLICT_NONE = 0;
+    private static final String[] CONFLICT_VALUES = new String[] {"", " OR ROLLBACK ", " OR ABORT ", " OR FAIL ", " OR IGNORE ", " OR REPLACE "};
+
+    /**
+     * Convenience method for updating rows in the database.
+     *
+     * @param table the table to update in
+     * @param values a map from column names to new column values. null is a
+     *            valid value that will be translated to NULL.
+     * @param whereClause the optional WHERE clause to apply when updating.
+     *            Passing null will update all rows.
+     * @param whereArgs You may include ?s in the where clause, which
+     *            will be replaced by the values from whereArgs. The values
+     *            will be bound as Strings.
+     * @return the number of rows affected
+     */
+    @RobocopTarget
+    public static int updateArrays(SQLiteDatabase db, String table, ContentValues[] values, UpdateOperation[] ops, String whereClause, String[] whereArgs) {
+        return updateArraysWithOnConflict(db, table, values, ops, whereClause, whereArgs, CONFLICT_NONE, true);
+    }
+
+    public static void updateArraysBlindly(SQLiteDatabase db, String table, ContentValues[] values, UpdateOperation[] ops, String whereClause, String[] whereArgs) {
+        updateArraysWithOnConflict(db, table, values, ops, whereClause, whereArgs, CONFLICT_NONE, false);
+    }
+
+    @RobocopTarget
+    public enum UpdateOperation {
+        /**
+         * ASSIGN is the usual update: replaces the value in the named column with the provided value.
+         *
+         * foo = ?
+         */
+        ASSIGN,
+
+        /**
+         * BITWISE_OR applies the provided value to the existing value with a bitwise OR. This is useful for adding to flags.
+         *
+         * foo |= ?
+         */
+        BITWISE_OR,
+
+        /**
+         * EXPRESSION is an end-run around the API: it allows callers to specify a fragment of SQL to splice into the
+         * SET part of the query.
+         *
+         * foo = $value
+         *
+         * Be very careful not to use user input in this.
+         */
+        EXPRESSION,
+    }
+
+    /**
+     * This is an evil reimplementation of SQLiteDatabase's methods to allow for
+     * smarter updating.
+     *
+     * Each ContentValues has an associated enum that describes how to unify input values with the existing column values.
+     */
+    private static int updateArraysWithOnConflict(SQLiteDatabase db, String table,
+                                          ContentValues[] values,
+                                          UpdateOperation[] ops,
+                                          String whereClause,
+                                          String[] whereArgs,
+                                          int conflictAlgorithm,
+                                          boolean returnChangedRows) {
+        if (values == null || values.length == 0) {
+            throw new IllegalArgumentException("Empty values");
+        }
+
+        if (ops == null || ops.length != values.length) {
+            throw new IllegalArgumentException("ops and values don't match");
+        }
+
+        StringBuilder sql = new StringBuilder(120);
+        sql.append("UPDATE ");
+        sql.append(CONFLICT_VALUES[conflictAlgorithm]);
+        sql.append(table);
+        sql.append(" SET ");
+
+        // move all bind args to one array
+        int setValuesSize = 0;
+        for (int i = 0; i < values.length; i++) {
+            // EXPRESSION types don't contribute any placeholders.
+            if (ops[i] != UpdateOperation.EXPRESSION) {
+                setValuesSize += values[i].size();
+            }
+        }
+
+        int bindArgsSize = (whereArgs == null) ? setValuesSize : (setValuesSize + whereArgs.length);
+        Object[] bindArgs = new Object[bindArgsSize];
+
+        int arg = 0;
+        for (int i = 0; i < values.length; i++) {
+            final ContentValues v = values[i];
+            final UpdateOperation op = ops[i];
+
+            // Alas, code duplication.
+            switch (op) {
+                case ASSIGN:
+                    for (Map.Entry<String, Object> entry : v.valueSet()) {
+                        final String colName = entry.getKey();
+                        sql.append((arg > 0) ? "," : "");
+                        sql.append(colName);
+                        bindArgs[arg++] = entry.getValue();
+                        sql.append("= ?");
+                    }
+                    break;
+                case BITWISE_OR:
+                    for (Map.Entry<String, Object> entry : v.valueSet()) {
+                        final String colName = entry.getKey();
+                        sql.append((arg > 0) ? "," : "");
+                        sql.append(colName);
+                        bindArgs[arg++] = entry.getValue();
+                        sql.append("= ? | ");
+                        sql.append(colName);
+                    }
+                    break;
+                case EXPRESSION:
+                    // Treat each value as a literal SQL string.
+                    for (Map.Entry<String, Object> entry : v.valueSet()) {
+                        final String colName = entry.getKey();
+                        sql.append((arg > 0) ? "," : "");
+                        sql.append(colName);
+                        sql.append(" = ");
+                        sql.append(entry.getValue());
+                    }
+                    break;
+            }
+        }
+
+        if (whereArgs != null) {
+            for (arg = setValuesSize; arg < bindArgsSize; arg++) {
+                bindArgs[arg] = whereArgs[arg - setValuesSize];
+            }
+        }
+        if (!TextUtils.isEmpty(whereClause)) {
+            sql.append(" WHERE ");
+            sql.append(whereClause);
+        }
+
+        // What a huge pain in the ass, all because SQLiteDatabase doesn't expose .executeSql,
+        // and we can't get a DB handle. Nor can we easily construct a statement with arguments
+        // already bound.
+        final SQLiteStatement statement = db.compileStatement(sql.toString());
+        try {
+            bindAllArgs(statement, bindArgs);
+            if (!returnChangedRows) {
+                statement.execute();
+                return 0;
+            }
+            // This is a separate method so we can annotate it with @TargetApi.
+            return executeStatementReturningChangedRows(statement);
+        } finally {
+            statement.close();
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
+    private static int executeStatementReturningChangedRows(SQLiteStatement statement) {
+        return statement.executeUpdateDelete();
+    }
+
+    // All because {@link SQLiteProgram#bind(integer, Object)} is private.
+    private static void bindAllArgs(SQLiteStatement statement, Object[] bindArgs) {
+        if (bindArgs == null) {
+            return;
+        }
+        for (int i = bindArgs.length; i != 0; i--) {
+            Object v = bindArgs[i - 1];
+            if (v == null) {
+                statement.bindNull(i);
+            } else if (v instanceof String) {
+                statement.bindString(i, (String) v);
+            } else if (v instanceof Double) {
+                statement.bindDouble(i, (Double) v);
+            } else if (v instanceof Float) {
+                statement.bindDouble(i, (Float) v);
+            } else if (v instanceof Long) {
+                statement.bindLong(i, (Long) v);
+            } else if (v instanceof Integer) {
+                statement.bindLong(i, (Integer) v);
+            } else if (v instanceof Byte) {
+                statement.bindLong(i, (Byte) v);
+            } else if (v instanceof byte[]) {
+                statement.bindBlob(i, (byte[]) v);
+            }
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/FormHistoryProvider.java

@@ -0,0 +1,166 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.lang.IllegalArgumentException;
+import java.util.HashMap;
+
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.db.BrowserContract.FormHistory;
+import org.mozilla.gecko.db.BrowserContract.DeletedFormHistory;
+import org.mozilla.gecko.db.BrowserContract;
+import org.mozilla.gecko.sqlite.SQLiteBridge;
+import org.mozilla.gecko.sync.Utils;
+
+import android.content.ContentValues;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.net.Uri;
+import android.text.TextUtils;
+
+public class FormHistoryProvider extends SQLiteBridgeContentProvider {
+    static final String TABLE_FORM_HISTORY = "moz_formhistory";
+    static final String TABLE_DELETED_FORM_HISTORY = "moz_deleted_formhistory";
+
+    private static final int FORM_HISTORY = 100;
+    private static final int DELETED_FORM_HISTORY = 101;
+
+    private static final UriMatcher URI_MATCHER;
+
+
+    // This should be kept in sync with the db version in toolkit/components/satchel/nsFormHistory.js
+    private static final int DB_VERSION = 4;
+    private static final String DB_FILENAME = "formhistory.sqlite";
+    private static final String TELEMETRY_TAG = "SQLITEBRIDGE_PROVIDER_FORMS";
+
+    private static final String WHERE_GUID_IS_NULL = BrowserContract.DeletedFormHistory.GUID + " IS NULL";
+    private static final String WHERE_GUID_IS_VALUE = BrowserContract.DeletedFormHistory.GUID + " = ?";
+
+    private static final String LOG_TAG = "FormHistoryProvider";
+
+    static {
+        URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
+        URI_MATCHER.addURI(BrowserContract.FORM_HISTORY_AUTHORITY, "formhistory", FORM_HISTORY);
+        URI_MATCHER.addURI(BrowserContract.FORM_HISTORY_AUTHORITY, "deleted-formhistory", DELETED_FORM_HISTORY);
+    }
+
+    public FormHistoryProvider() {
+        super(LOG_TAG);
+    }
+
+
+    @Override
+    public String getType(Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+
+        switch (match) {
+            case FORM_HISTORY:
+                return FormHistory.CONTENT_TYPE;
+
+            case DELETED_FORM_HISTORY:
+                return DeletedFormHistory.CONTENT_TYPE;
+
+            default:
+                throw new UnsupportedOperationException("Unknown type " + uri);
+        }
+    }
+
+    @Override
+    public String getTable(Uri uri) {
+        String table = null;
+        final int match = URI_MATCHER.match(uri);
+        switch (match) {
+            case DELETED_FORM_HISTORY:
+                table = TABLE_DELETED_FORM_HISTORY;
+                break;
+
+            case FORM_HISTORY:
+                table = TABLE_FORM_HISTORY;
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown table " + uri);
+        }
+        return table;
+    }
+
+    @Override
+    public String getSortOrder(Uri uri, String aRequested) {
+        if (!TextUtils.isEmpty(aRequested)) {
+            return aRequested;
+        }
+
+        return null;
+    }
+
+    @Override
+    public void setupDefaults(Uri uri, ContentValues values) {
+        int match = URI_MATCHER.match(uri);
+        long now = System.currentTimeMillis();
+
+        switch (match) {
+            case DELETED_FORM_HISTORY:
+                values.put(DeletedFormHistory.TIME_DELETED, now);
+
+                // Deleted entries must contain a guid
+                if (!values.containsKey(FormHistory.GUID)) {
+                    throw new IllegalArgumentException("Must provide a GUID for a deleted form history");
+                }
+                break;
+
+            case FORM_HISTORY:
+                // Generate GUID for new entry. Don't override specified GUIDs.
+                if (!values.containsKey(FormHistory.GUID)) {
+                    String guid = Utils.generateGuid();
+                    values.put(FormHistory.GUID, guid);
+                }
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown insert URI " + uri);
+        }
+    }
+
+    @Override
+    public void initGecko() {
+        GeckoAppShell.notifyObservers("FormHistory:Init", null);
+    }
+
+    @Override
+    public void onPreInsert(ContentValues values, Uri uri, SQLiteBridge db) {
+        if (!values.containsKey(FormHistory.GUID)) {
+            return;
+        }
+
+        String guid = values.getAsString(FormHistory.GUID);
+        if (guid == null) {
+            db.delete(TABLE_DELETED_FORM_HISTORY, WHERE_GUID_IS_NULL, null);
+            return;
+        }
+        String[] args = new String[] { guid };
+        db.delete(TABLE_DELETED_FORM_HISTORY, WHERE_GUID_IS_VALUE, args);
+     }
+
+    @Override
+    public void onPreUpdate(ContentValues values, Uri uri, SQLiteBridge db) { }
+
+    @Override
+    public void onPostQuery(Cursor cursor, Uri uri, SQLiteBridge db) { }
+
+    @Override
+    protected String getDBName() {
+        return DB_FILENAME;
+    }
+
+    @Override
+    protected String getTelemetryPrefix() {
+        return TELEMETRY_TAG;
+    }
+
+    @Override
+    protected int getDBVersion() {
+        return DB_VERSION;
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/HomeProvider.java

@@ -0,0 +1,194 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.io.IOException;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.mozilla.gecko.R;
+import org.mozilla.gecko.db.BrowserContract.HomeItems;
+import org.mozilla.gecko.db.DBUtils;
+import org.mozilla.gecko.sqlite.SQLiteBridge;
+import org.mozilla.gecko.util.RawResource;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.net.Uri;
+import android.util.Log;
+
+public class HomeProvider extends SQLiteBridgeContentProvider {
+    private static final String LOGTAG = "GeckoHomeProvider";
+
+    // This should be kept in sync with the db version in mobile/android/modules/HomeProvider.jsm
+    private static final int DB_VERSION = 3;
+    private static final String DB_FILENAME = "home.sqlite";
+    private static final String TELEMETRY_TAG = "SQLITEBRIDGE_PROVIDER_HOME";
+
+    private static final String TABLE_ITEMS = "items";
+
+    // Endpoint to return static fake data.
+    static final int ITEMS_FAKE = 100;
+    static final int ITEMS = 101;
+    static final int ITEMS_ID = 102;
+
+    static final UriMatcher URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
+
+    static {
+        URI_MATCHER.addURI(BrowserContract.HOME_AUTHORITY, "items/fake", ITEMS_FAKE);
+        URI_MATCHER.addURI(BrowserContract.HOME_AUTHORITY, "items", ITEMS);
+        URI_MATCHER.addURI(BrowserContract.HOME_AUTHORITY, "items/#", ITEMS_ID);
+    }
+
+    public HomeProvider() {
+        super(LOGTAG);
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+
+        switch (match) {
+            case ITEMS_FAKE: {
+                return HomeItems.CONTENT_TYPE;
+            }
+            case ITEMS: {
+                return HomeItems.CONTENT_TYPE;
+            }
+            default: {
+                throw new UnsupportedOperationException("Unknown type " + uri);
+            }
+        }
+    }
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
+        final int match = URI_MATCHER.match(uri);
+
+        // If we're querying the fake items, don't try to get the database.
+        if (match == ITEMS_FAKE) {
+            return queryFakeItems(uri, projection, selection, selectionArgs, sortOrder);
+        }
+
+        final String datasetId = uri.getQueryParameter(BrowserContract.PARAM_DATASET_ID);
+        if (datasetId == null) {
+            throw new IllegalArgumentException("All queries should contain a dataset ID parameter");
+        }
+
+        selection = DBUtils.concatenateWhere(selection, HomeItems.DATASET_ID + " = ?");
+        selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                                                    new String[] { datasetId });
+
+        // Otherwise, let the SQLiteContentProvider implementation take care of this query for us!
+        Cursor c = super.query(uri, projection, selection, selectionArgs, sortOrder);
+
+        // SQLiteBridgeContentProvider may return a null Cursor if the database hasn't been created yet.
+        // However, we need a non-null cursor in order to listen for notifications.
+        if (c == null) {
+            c = new MatrixCursor(projection != null ? projection : HomeItems.DEFAULT_PROJECTION);
+        }
+
+        final ContentResolver cr = getContext().getContentResolver();
+        c.setNotificationUri(cr, getDatasetNotificationUri(datasetId));
+
+        return c;
+    }
+
+    /**
+     * Returns a cursor populated with static fake data.
+     */
+    private Cursor queryFakeItems(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
+        JSONArray items = null;
+        try {
+            final String jsonString = RawResource.getAsString(getContext(), R.raw.fake_home_items);
+            items = new JSONArray(jsonString);
+        } catch (IOException e) {
+            Log.e(LOGTAG, "Error getting fake home items", e);
+            return null;
+        } catch (JSONException e) {
+            Log.e(LOGTAG, "Error parsing fake_home_items.json", e);
+            return null;
+        }
+
+        final MatrixCursor c = new MatrixCursor(HomeItems.DEFAULT_PROJECTION);
+        for (int i = 0; i < items.length(); i++) {
+            try {
+                final JSONObject item = items.getJSONObject(i);
+                c.addRow(new Object[] {
+                    item.getInt("id"),
+                    item.getString("dataset_id"),
+                    item.getString("url"),
+                    item.getString("title"),
+                    item.getString("description"),
+                    item.getString("image_url"),
+                    item.getString("filter")
+                });
+            } catch (JSONException e) {
+                Log.e(LOGTAG, "Error creating cursor row for fake home item", e);
+            }
+        }
+        return c;
+    }
+
+    /**
+     * SQLiteBridgeContentProvider implementation
+     */
+
+    @Override
+    protected String getDBName() {
+        return DB_FILENAME;
+    }
+
+    @Override
+    protected String getTelemetryPrefix() {
+        return TELEMETRY_TAG;
+    }
+
+    @Override
+    protected int getDBVersion() {
+        return DB_VERSION;
+    }
+
+    @Override
+    public String getTable(Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+        switch (match) {
+            case ITEMS: {
+                return TABLE_ITEMS;
+            }
+            default: {
+                throw new UnsupportedOperationException("Unknown table " + uri);
+            }
+        }
+    }
+
+    @Override
+    public String getSortOrder(Uri uri, String aRequested) {
+        return null;
+    }
+
+    @Override
+    public void setupDefaults(Uri uri, ContentValues values) { }
+
+    @Override
+    public void initGecko() { }
+
+    @Override
+    public void onPreInsert(ContentValues values, Uri uri, SQLiteBridge db) { }
+
+    @Override
+    public void onPreUpdate(ContentValues values, Uri uri, SQLiteBridge db) { }
+
+    @Override
+    public void onPostQuery(Cursor cursor, Uri uri, SQLiteBridge db) { }
+
+    public static Uri getDatasetNotificationUri(String datasetId) {
+        return Uri.withAppendedPath(HomeItems.CONTENT_URI, datasetId);
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/LocalSearches.java

@@ -0,0 +1,28 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.net.Uri;
+
+/**
+ * Helper class for dealing with the search provider inside Fennec.
+ */
+public class LocalSearches implements Searches {
+    private final Uri uriWithProfile;
+
+    public LocalSearches(String mProfile) {
+        uriWithProfile = DBUtils.appendProfileWithDefault(mProfile, BrowserContract.SearchHistory.CONTENT_URI);
+    }
+
+    @Override
+    public void insert(ContentResolver cr, String query) {
+        final ContentValues values = new ContentValues();
+        values.put(BrowserContract.SearchHistory.QUERY, query);
+        cr.insert(uriWithProfile, values);
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/LocalTabsAccessor.java

@@ -0,0 +1,320 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.mozilla.gecko.Tab;
+import org.mozilla.gecko.util.ThreadUtils;
+import org.mozilla.gecko.util.UIAsyncTask;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+public class LocalTabsAccessor implements TabsAccessor {
+    private static final String LOGTAG = "GeckoTabsAccessor";
+    private static final long THREE_WEEKS_IN_MILLISECONDS = TimeUnit.MILLISECONDS.convert(21L, TimeUnit.DAYS);
+
+    public static final String[] TABS_PROJECTION_COLUMNS = new String[] {
+                                                                BrowserContract.Tabs.TITLE,
+                                                                BrowserContract.Tabs.URL,
+                                                                BrowserContract.Clients.GUID,
+                                                                BrowserContract.Clients.NAME,
+                                                                BrowserContract.Tabs.LAST_USED,
+                                                                BrowserContract.Clients.LAST_MODIFIED,
+                                                                BrowserContract.Clients.DEVICE_TYPE,
+                                                            };
+
+    public static final String[] CLIENTS_PROJECTION_COLUMNS = new String[] {
+                                                                    BrowserContract.Clients.GUID,
+                                                                    BrowserContract.Clients.NAME,
+                                                                    BrowserContract.Clients.LAST_MODIFIED,
+                                                                    BrowserContract.Clients.DEVICE_TYPE
+                                                            };
+
+    private static final String REMOTE_CLIENTS_SELECTION = BrowserContract.Clients.GUID + " IS NOT NULL";
+    private static final String LOCAL_TABS_SELECTION = BrowserContract.Tabs.CLIENT_GUID + " IS NULL";
+    private static final String REMOTE_TABS_SELECTION = BrowserContract.Tabs.CLIENT_GUID + " IS NOT NULL";
+    private static final String REMOTE_TABS_SELECTION_CLIENT_RECENCY = REMOTE_TABS_SELECTION +
+            " AND " + BrowserContract.Clients.LAST_MODIFIED + " > ?";
+
+    private static final String REMOTE_TABS_SORT_ORDER =
+            // Most recently synced clients first.
+            BrowserContract.Clients.LAST_MODIFIED + " DESC, " +
+            // If two clients somehow had the same last modified time, this will
+            // group them (arbitrarily).
+            BrowserContract.Clients.GUID + " DESC, " +
+            // Within a single client, most recently used tabs first.
+            BrowserContract.Tabs.LAST_USED + " DESC";
+
+    private static final String LOCAL_CLIENT_SELECTION = BrowserContract.Clients.GUID + " IS NULL";
+
+    private static final Pattern FILTERED_URL_PATTERN = Pattern.compile("^(about|chrome|wyciwyg|file):");
+
+    private final Uri clientsRecencyUriWithProfile;
+    private final Uri tabsUriWithProfile;
+    private final Uri clientsUriWithProfile;
+
+    public LocalTabsAccessor(String profileName) {
+        tabsUriWithProfile = DBUtils.appendProfileWithDefault(profileName, BrowserContract.Tabs.CONTENT_URI);
+        clientsUriWithProfile = DBUtils.appendProfileWithDefault(profileName, BrowserContract.Clients.CONTENT_URI);
+        clientsRecencyUriWithProfile = DBUtils.appendProfileWithDefault(profileName, BrowserContract.Clients.CONTENT_RECENCY_URI);
+    }
+
+    /**
+     * Extracts a List of just RemoteClients from a cursor.
+     * The supplied cursor should be grouped by guid and sorted by most recently used.
+     */
+    @Override
+    public List<RemoteClient> getClientsWithoutTabsByRecencyFromCursor(Cursor cursor) {
+        final ArrayList<RemoteClient> clients = new ArrayList<>(cursor.getCount());
+
+        final int originalPosition = cursor.getPosition();
+        try {
+            if (!cursor.moveToFirst()) {
+                return clients;
+            }
+
+            final int clientGuidIndex = cursor.getColumnIndex(BrowserContract.Clients.GUID);
+            final int clientNameIndex = cursor.getColumnIndex(BrowserContract.Clients.NAME);
+            final int clientLastModifiedIndex = cursor.getColumnIndex(BrowserContract.Clients.LAST_MODIFIED);
+            final int clientDeviceTypeIndex = cursor.getColumnIndex(BrowserContract.Clients.DEVICE_TYPE);
+
+            while (!cursor.isAfterLast()) {
+                final String clientGuid = cursor.getString(clientGuidIndex);
+                final String clientName = cursor.getString(clientNameIndex);
+                final String deviceType = cursor.getString(clientDeviceTypeIndex);
+                final long lastModified = cursor.getLong(clientLastModifiedIndex);
+
+                clients.add(new RemoteClient(clientGuid, clientName, lastModified, deviceType));
+
+                cursor.moveToNext();
+            }
+        } finally {
+            cursor.moveToPosition(originalPosition);
+        }
+        return clients;
+    }
+
+    /**
+     * Extract client and tab records from a cursor.
+     * <p>
+     * The position of the cursor is moved to before the first record before
+     * reading. The cursor is advanced until there are no more records to be
+     * read. The position of the cursor is restored before returning.
+     *
+     * @param cursor
+     *            to extract records from. The records should already be grouped
+     *            by client GUID.
+     * @return list of clients, each containing list of tabs.
+     */
+    @Override
+    public List<RemoteClient> getClientsFromCursor(final Cursor cursor) {
+        final ArrayList<RemoteClient> clients = new ArrayList<RemoteClient>();
+
+        final int originalPosition = cursor.getPosition();
+        try {
+            if (!cursor.moveToFirst()) {
+                return clients;
+            }
+
+            final int tabTitleIndex = cursor.getColumnIndex(BrowserContract.Tabs.TITLE);
+            final int tabUrlIndex = cursor.getColumnIndex(BrowserContract.Tabs.URL);
+            final int tabLastUsedIndex = cursor.getColumnIndex(BrowserContract.Tabs.LAST_USED);
+            final int clientGuidIndex = cursor.getColumnIndex(BrowserContract.Clients.GUID);
+            final int clientNameIndex = cursor.getColumnIndex(BrowserContract.Clients.NAME);
+            final int clientLastModifiedIndex = cursor.getColumnIndex(BrowserContract.Clients.LAST_MODIFIED);
+            final int clientDeviceTypeIndex = cursor.getColumnIndex(BrowserContract.Clients.DEVICE_TYPE);
+
+            // A walking partition, chunking by client GUID. We assume the
+            // cursor records are already grouped by client GUID; see the query
+            // sort order.
+            RemoteClient lastClient = null;
+            while (!cursor.isAfterLast()) {
+                final String clientGuid = cursor.getString(clientGuidIndex);
+                if (lastClient == null || !TextUtils.equals(lastClient.guid, clientGuid)) {
+                    final String clientName = cursor.getString(clientNameIndex);
+                    final long lastModified = cursor.getLong(clientLastModifiedIndex);
+                    final String deviceType = cursor.getString(clientDeviceTypeIndex);
+                    lastClient = new RemoteClient(clientGuid, clientName, lastModified, deviceType);
+                    clients.add(lastClient);
+                }
+
+                final String tabTitle = cursor.getString(tabTitleIndex);
+                final String tabUrl = cursor.getString(tabUrlIndex);
+                final long tabLastUsed = cursor.getLong(tabLastUsedIndex);
+                lastClient.tabs.add(new RemoteTab(tabTitle, tabUrl, tabLastUsed));
+
+                cursor.moveToNext();
+            }
+        } finally {
+            cursor.moveToPosition(originalPosition);
+        }
+
+        return clients;
+    }
+
+    @Override
+    public Cursor getRemoteClientsByRecencyCursor(Context context) {
+        final Uri uri = clientsRecencyUriWithProfile;
+        return context.getContentResolver().query(uri, CLIENTS_PROJECTION_COLUMNS,
+                REMOTE_CLIENTS_SELECTION, null, null);
+    }
+
+    @Override
+    public Cursor getRemoteTabsCursor(Context context) {
+        return getRemoteTabsCursor(context, -1);
+    }
+
+    @Override
+    public Cursor getRemoteTabsCursor(Context context, int limit) {
+        Uri uri = tabsUriWithProfile;
+
+        if (limit > 0) {
+            uri = uri.buildUpon()
+                     .appendQueryParameter(BrowserContract.PARAM_LIMIT, String.valueOf(limit))
+                     .build();
+        }
+
+        final String threeWeeksAgoTimestampMillis = Long.valueOf(
+                System.currentTimeMillis() - THREE_WEEKS_IN_MILLISECONDS).toString();
+        return context.getContentResolver().query(uri,
+                                                            TABS_PROJECTION_COLUMNS,
+                                                            REMOTE_TABS_SELECTION_CLIENT_RECENCY,
+                                                            new String[] {threeWeeksAgoTimestampMillis},
+                                                            REMOTE_TABS_SORT_ORDER);
+    }
+
+    // This method returns all tabs from all remote clients,
+    // ordered by most recent client first, most recent tab first
+    @Override
+    public void getTabs(final Context context, final OnQueryTabsCompleteListener listener) {
+        getTabs(context, 0, listener);
+    }
+
+    // This method returns limited number of tabs from all remote clients,
+    // ordered by most recent client first, most recent tab first
+    @Override
+    public void getTabs(final Context context, final int limit, final OnQueryTabsCompleteListener listener) {
+        // If there is no listener, no point in doing work.
+        if (listener == null)
+            return;
+
+        (new UIAsyncTask.WithoutParams<List<RemoteClient>>(ThreadUtils.getBackgroundHandler()) {
+            @Override
+            protected List<RemoteClient> doInBackground() {
+                final Cursor cursor = getRemoteTabsCursor(context, limit);
+                if (cursor == null)
+                    return null;
+
+                try {
+                    return Collections.unmodifiableList(getClientsFromCursor(cursor));
+                } finally {
+                    cursor.close();
+                }
+            }
+
+            @Override
+            protected void onPostExecute(List<RemoteClient> clients) {
+                listener.onQueryTabsComplete(clients);
+            }
+        }).execute();
+    }
+
+    // Updates the modified time of the local client with the current time.
+    private void updateLocalClient(final ContentResolver cr) {
+        ContentValues values = new ContentValues();
+        values.put(BrowserContract.Clients.LAST_MODIFIED, System.currentTimeMillis());
+
+        cr.update(clientsUriWithProfile, values, LOCAL_CLIENT_SELECTION, null);
+    }
+
+    // Deletes all local tabs.
+    private void deleteLocalTabs(final ContentResolver cr) {
+        cr.delete(tabsUriWithProfile, LOCAL_TABS_SELECTION, null);
+    }
+
+    /**
+     * Tabs are positioned in the DB in the same order that they appear in the tabs param.
+     *   - URL should never empty or null. Skip this tab if there's no URL.
+     *   - TITLE should always a string, either a page title or empty.
+     *   - LAST_USED should always be numeric.
+     *   - FAVICON should be a URL or null.
+     *   - HISTORY should be serialized JSON array of URLs.
+     *   - POSITION should always be numeric.
+     *   - CLIENT_GUID should always be null to represent the local client.
+     */
+    private void insertLocalTabs(final ContentResolver cr, final Iterable<Tab> tabs) {
+        // Reuse this for serializing individual history URLs as JSON.
+        JSONArray history = new JSONArray();
+        ArrayList<ContentValues> valuesToInsert = new ArrayList<ContentValues>();
+
+        int position = 0;
+        for (Tab tab : tabs) {
+            // Skip this tab if it has a null URL or is in private browsing mode, or is a filtered URL.
+            String url = tab.getURL();
+            if (url == null || tab.isPrivate() || isFilteredURL(url))
+                continue;
+
+            ContentValues values = new ContentValues();
+            values.put(BrowserContract.Tabs.URL, url);
+            values.put(BrowserContract.Tabs.TITLE, tab.getTitle());
+            values.put(BrowserContract.Tabs.LAST_USED, tab.getLastUsed());
+
+            String favicon = tab.getFaviconURL();
+            if (favicon != null)
+                values.put(BrowserContract.Tabs.FAVICON, favicon);
+            else
+                values.putNull(BrowserContract.Tabs.FAVICON);
+
+            // We don't have access to session history in Java, so for now, we'll
+            // just use a JSONArray that holds most recent history item.
+            try {
+                history.put(0, tab.getURL());
+                values.put(BrowserContract.Tabs.HISTORY, history.toString());
+            } catch (JSONException e) {
+                Log.w(LOGTAG, "JSONException adding URL to tab history array.", e);
+            }
+
+            values.put(BrowserContract.Tabs.POSITION, position++);
+
+            // A null client guid corresponds to the local client.
+            values.putNull(BrowserContract.Tabs.CLIENT_GUID);
+
+            valuesToInsert.add(values);
+        }
+
+        ContentValues[] valuesToInsertArray = valuesToInsert.toArray(new ContentValues[valuesToInsert.size()]);
+        cr.bulkInsert(tabsUriWithProfile, valuesToInsertArray);
+    }
+
+    // Deletes all local tabs and replaces them with a new list of tabs.
+    @Override
+    public synchronized void persistLocalTabs(final ContentResolver cr, final Iterable<Tab> tabs) {
+        deleteLocalTabs(cr);
+        insertLocalTabs(cr, tabs);
+        updateLocalClient(cr);
+    }
+
+    /**
+     * Matches the supplied URL string against the set of URLs to filter.
+     *
+     * @return true if the supplied URL should be skipped; false otherwise.
+     */
+    private boolean isFilteredURL(String url) {
+        return FILTERED_URL_PATTERN.matcher(url).lookingAt();
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/LocalURLMetadata.java

@@ -0,0 +1,240 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.mozilla.gecko.db;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.icons.decoders.LoadFaviconResult;
+import org.mozilla.gecko.util.ThreadUtils;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+import android.util.LruCache;
+
+// Holds metadata info about URLs. Supports some helper functions for getting back a HashMap of key value data.
+public class LocalURLMetadata implements URLMetadata {
+    private static final String LOGTAG = "GeckoURLMetadata";
+    private final Uri uriWithProfile;
+
+    public LocalURLMetadata(String mProfile) {
+        uriWithProfile = DBUtils.appendProfileWithDefault(mProfile, URLMetadataTable.CONTENT_URI);
+    }
+
+    // A list of columns in the table. It's used to simplify some loops for reading/writing data.
+    private static final Set<String> COLUMNS;
+    static {
+        final HashSet<String> tempModel = new HashSet<>(4);
+        tempModel.add(URLMetadataTable.URL_COLUMN);
+        tempModel.add(URLMetadataTable.TILE_IMAGE_URL_COLUMN);
+        tempModel.add(URLMetadataTable.TILE_COLOR_COLUMN);
+        tempModel.add(URLMetadataTable.TOUCH_ICON_COLUMN);
+        COLUMNS = Collections.unmodifiableSet(tempModel);
+    }
+
+    // Store a cache of recent results. This number is chosen to match the max number of tiles on about:home
+    private static final int CACHE_SIZE = 9;
+    // Note: Members of this cache are unmodifiable.
+    private final LruCache<String, Map<String, Object>> cache = new LruCache<String, Map<String, Object>>(CACHE_SIZE);
+
+    /**
+     * Converts a JSON object into a unmodifiable Map of known metadata properties.
+     * Will throw away any properties that aren't stored in the database.
+     *
+     * Incoming data can include a list like: {touchIconList:{56:"http://x.com/56.png", 76:"http://x.com/76.png"}}.
+     * This will then be filtered to find the most appropriate touchIcon, i.e. the closest icon size that is larger
+     * than (or equal to) the preferred homescreen launcher icon size, which is then stored in the "touchIcon" property.
+     */
+    @Override
+    public Map<String, Object> fromJSON(JSONObject obj) {
+        Map<String, Object> data = new HashMap<String, Object>();
+
+        for (String key : COLUMNS) {
+            if (obj.has(key)) {
+                data.put(key, obj.optString(key));
+            }
+        }
+
+
+        try {
+            JSONObject icons;
+            if (obj.has("touchIconList") &&
+                    (icons = obj.getJSONObject("touchIconList")).length() > 0) {
+                int preferredSize = GeckoAppShell.getPreferredIconSize();
+
+                Iterator<String> keys = icons.keys();
+
+                ArrayList<Integer> sizes = new ArrayList<Integer>(icons.length());
+                while (keys.hasNext()) {
+                    sizes.add(new Integer(keys.next()));
+                }
+
+                final int bestSize = LoadFaviconResult.selectBestSizeFromList(sizes, preferredSize);
+                final String iconURL = icons.getString(Integer.toString(bestSize));
+
+                data.put(URLMetadataTable.TOUCH_ICON_COLUMN, iconURL);
+            }
+        } catch (JSONException e) {
+            Log.w(LOGTAG, "Exception processing touchIconList for LocalURLMetadata; ignoring.", e);
+        }
+
+        return Collections.unmodifiableMap(data);
+    }
+
+    /**
+     * Converts a Cursor into a unmodifiable Map of known metadata properties.
+     * Will throw away any properties that aren't stored in the database.
+     * Will also not iterate through multiple rows in the cursor.
+     */
+    private Map<String, Object> fromCursor(Cursor c) {
+        Map<String, Object> data = new HashMap<String, Object>();
+
+        String[] columns = c.getColumnNames();
+        for (String column : columns) {
+            if (COLUMNS.contains(column)) {
+                try {
+                    data.put(column, c.getString(c.getColumnIndexOrThrow(column)));
+                } catch (Exception ex) {
+                    Log.i(LOGTAG, "Error getting data for " + column, ex);
+                }
+            }
+        }
+
+        return Collections.unmodifiableMap(data);
+    }
+
+    /**
+     * Returns an unmodifiable Map of url->Metadata (i.e. A second HashMap) for a list of urls.
+     * Must not be called from UI or Gecko threads.
+     */
+    @Override
+    public Map<String, Map<String, Object>> getForURLs(final ContentResolver cr,
+                                                       final Collection<String> urls,
+                                                       final List<String> requestedColumns) {
+        ThreadUtils.assertNotOnUiThread();
+        ThreadUtils.assertNotOnGeckoThread();
+
+        final Map<String, Map<String, Object>> data = new HashMap<String, Map<String, Object>>();
+
+        // Nothing to query for
+        if (urls.isEmpty() || requestedColumns.isEmpty()) {
+            Log.e(LOGTAG, "Queried metadata for nothing");
+            return data;
+        }
+
+        // Search the cache for any of these urls
+        List<String> urlsToQuery = new ArrayList<String>();
+        for (String url : urls) {
+            final Map<String, Object> hit = cache.get(url);
+            if (hit != null) {
+                // Cache hit: we've found the URL in the cache, however we may not have cached the desired columns
+                // for that URL. Hence we need to check whether our cache hit contains those columns, and directly
+                // retrieve the desired data if not. (E.g. the top sites panel retrieves the tile, and tilecolor. If
+                // we later try to retrieve the touchIcon for a top-site the cache hit will only point to
+                // tile+tilecolor, and not the required touchIcon. In this case we don't want to use the cache.)
+                boolean useCache = true;
+                for (String c: requestedColumns) {
+                    if (!hit.containsKey(c)) {
+                        useCache = false;
+                    }
+                }
+                if (useCache) {
+                    data.put(url, hit);
+                } else {
+                    urlsToQuery.add(url);
+                }
+            } else {
+                urlsToQuery.add(url);
+            }
+        }
+
+        // If everything was in the cache, we're done!
+        if (urlsToQuery.size() == 0) {
+            return Collections.unmodifiableMap(data);
+        }
+
+        final String selection = DBUtils.computeSQLInClause(urlsToQuery.size(), URLMetadataTable.URL_COLUMN);
+        List<String> columns = requestedColumns;
+        // We need the url to build our final HashMap, so we force it to be included in the query.
+        if (!columns.contains(URLMetadataTable.URL_COLUMN)) {
+            // The requestedColumns may be immutable (e.g. if the caller used Collections.singletonList), hence
+            // we have to create a copy.
+            columns = new ArrayList<String>(columns);
+            columns.add(URLMetadataTable.URL_COLUMN);
+        }
+
+        final Cursor cursor = cr.query(uriWithProfile,
+                                       columns.toArray(new String[columns.size()]), // columns,
+                                       selection, // selection
+                                       urlsToQuery.toArray(new String[urlsToQuery.size()]), // selectionargs
+                                       null);
+        try {
+            if (!cursor.moveToFirst()) {
+                return Collections.unmodifiableMap(data);
+            }
+
+            do {
+                final Map<String, Object> metadata = fromCursor(cursor);
+                final String url = cursor.getString(cursor.getColumnIndexOrThrow(URLMetadataTable.URL_COLUMN));
+
+                data.put(url, metadata);
+                cache.put(url, metadata);
+            } while (cursor.moveToNext());
+
+        } finally {
+            cursor.close();
+        }
+
+        return Collections.unmodifiableMap(data);
+    }
+
+    /**
+     * Saves a HashMap of metadata into the database. Will iterate through columns
+     * in the Database and only save rows with matching keys in the HashMap.
+     * Must not be called from UI or Gecko threads.
+     */
+    @Override
+    public void save(final ContentResolver cr, final Map<String, Object> data) {
+        ThreadUtils.assertNotOnUiThread();
+        ThreadUtils.assertNotOnGeckoThread();
+
+        try {
+            ContentValues values = new ContentValues();
+
+            for (String key : COLUMNS) {
+                if (data.containsKey(key)) {
+                    values.put(key, (String) data.get(key));
+                }
+            }
+
+            if (values.size() == 0) {
+                return;
+            }
+
+            Uri uri = uriWithProfile.buildUpon()
+                                 .appendQueryParameter(BrowserContract.PARAM_INSERT_IF_NEEDED, "true")
+                                 .build();
+            cr.update(uri, values, URLMetadataTable.URL_COLUMN + "=?", new String[] {
+                (String) data.get(URLMetadataTable.URL_COLUMN)
+            });
+        } catch (Exception ex) {
+            Log.e(LOGTAG, "error saving", ex);
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/LocalUrlAnnotations.java

@@ -0,0 +1,253 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.net.Uri;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.util.Log;
+
+import org.json.JSONException;
+import org.mozilla.gecko.annotation.RobocopTarget;
+import org.mozilla.gecko.db.BrowserContract.UrlAnnotations.Key;
+import org.mozilla.gecko.feeds.subscriptions.FeedSubscription;
+
+public class LocalUrlAnnotations implements UrlAnnotations {
+    private static final String LOGTAG = "LocalUrlAnnotations";
+
+    private Uri urlAnnotationsTableWithProfile;
+
+    public LocalUrlAnnotations(final String profile) {
+        urlAnnotationsTableWithProfile = DBUtils.appendProfile(profile, BrowserContract.UrlAnnotations.CONTENT_URI);
+    }
+
+    /**
+     * Get all feed subscriptions.
+     */
+    @Override
+    public Cursor getFeedSubscriptions(ContentResolver cr) {
+        return queryByKey(cr,
+                Key.FEED_SUBSCRIPTION,
+                new String[] { BrowserContract.UrlAnnotations.URL, BrowserContract.UrlAnnotations.VALUE },
+                null);
+    }
+
+    /**
+     * Insert mapping from website URL to URL of the feed.
+     */
+    @Override
+    public void insertFeedUrl(ContentResolver cr, String originUrl, String feedUrl) {
+        insertAnnotation(cr, originUrl, Key.FEED, feedUrl);
+    }
+
+    @Override
+    public boolean hasAcceptedOrDeclinedHomeScreenShortcut(ContentResolver cr, String url) {
+        return hasResultsForSelection(cr,
+                BrowserContract.UrlAnnotations.URL + " = ?",
+                new String[]{url});
+    }
+
+    @Override
+    public void insertHomeScreenShortcut(ContentResolver cr, String url, boolean hasCreatedShortCut) {
+        insertAnnotation(cr, url, Key.HOME_SCREEN_SHORTCUT, String.valueOf(hasCreatedShortCut));
+    }
+
+    /**
+     * Returns true if there's a mapping from the given website URL to a feed URL. False otherwise.
+     */
+    @Override
+    public boolean hasFeedUrlForWebsite(ContentResolver cr, String websiteUrl) {
+        return hasResultsForSelection(cr,
+                BrowserContract.UrlAnnotations.URL + " = ? AND " + BrowserContract.UrlAnnotations.KEY + " = ?",
+                new String[]{websiteUrl, Key.FEED.getDbValue()});
+    }
+
+    /**
+     * Returns true if there's a website URL with this feed URL. False otherwise.
+     */
+    @Override
+    public boolean hasWebsiteForFeedUrl(ContentResolver cr, String feedUrl) {
+        return hasResultsForSelection(cr,
+                BrowserContract.UrlAnnotations.VALUE + " = ? AND " + BrowserContract.UrlAnnotations.KEY + " = ?",
+                new String[]{feedUrl, Key.FEED.getDbValue()});
+    }
+
+    /**
+     * Delete the feed URL mapping for this website URL.
+     */
+    @Override
+    public void deleteFeedUrl(ContentResolver cr, String websiteUrl) {
+        deleteAnnotation(cr, websiteUrl, Key.FEED);
+    }
+
+    /**
+     * Get website URLs that are mapped to the given feed URL.
+     */
+    @Override
+    public Cursor getWebsitesWithFeedUrl(ContentResolver cr) {
+        return cr.query(urlAnnotationsTableWithProfile,
+                new String[] { BrowserContract.UrlAnnotations.URL },
+                BrowserContract.UrlAnnotations.KEY + " = ?",
+                new String[] { Key.FEED.getDbValue() },
+                null);
+    }
+
+    /**
+     * Returns true if there's a subscription for this feed URL. False otherwise.
+     */
+    @Override
+    public boolean hasFeedSubscription(ContentResolver cr, String feedUrl) {
+        return hasResultsForSelection(cr,
+                BrowserContract.UrlAnnotations.URL + " = ? AND " + BrowserContract.UrlAnnotations.KEY + " = ?",
+                new String[]{feedUrl, Key.FEED_SUBSCRIPTION.getDbValue()});
+    }
+
+    /**
+     * Insert the given feed subscription (Mapping from feed URL to the subscription object).
+     */
+    @Override
+    public void insertFeedSubscription(ContentResolver cr, FeedSubscription subscription) {
+        try {
+            insertAnnotation(cr, subscription.getFeedUrl(), Key.FEED_SUBSCRIPTION, subscription.toJSON().toString());
+        } catch (JSONException e) {
+            Log.w(LOGTAG, "Could not serialize subscription");
+        }
+    }
+
+    /**
+     * Update the feed subscription with new values.
+     */
+    @Override
+    public void updateFeedSubscription(ContentResolver cr, FeedSubscription subscription) {
+        try {
+            updateAnnotation(cr, subscription.getFeedUrl(), Key.FEED_SUBSCRIPTION, subscription.toJSON().toString());
+        } catch (JSONException e) {
+            Log.w(LOGTAG, "Could not serialize subscription");
+        }
+    }
+
+    /**
+     * Delete the subscription for the feed URL.
+     */
+    @Override
+    public void deleteFeedSubscription(ContentResolver cr, FeedSubscription subscription) {
+        deleteAnnotation(cr, subscription.getFeedUrl(), Key.FEED_SUBSCRIPTION);
+    }
+
+    private int deleteAnnotation(final ContentResolver cr, final String url, final Key key) {
+        return cr.delete(urlAnnotationsTableWithProfile,
+                BrowserContract.UrlAnnotations.KEY + " = ? AND " + BrowserContract.UrlAnnotations.URL + " = ?",
+                new String[] { key.getDbValue(), url  });
+    }
+
+    private int updateAnnotation(final ContentResolver cr, final String url, final Key key, final String value) {
+        ContentValues values = new ContentValues();
+        values.put(BrowserContract.UrlAnnotations.VALUE, value);
+        values.put(BrowserContract.UrlAnnotations.DATE_MODIFIED, System.currentTimeMillis());
+
+        return cr.update(urlAnnotationsTableWithProfile,
+                values,
+                BrowserContract.UrlAnnotations.KEY + " = ? AND " + BrowserContract.UrlAnnotations.URL + " = ?",
+                new String[]{key.getDbValue(), url});
+    }
+
+    private void insertAnnotation(final ContentResolver cr, final String url, final Key key, final String value) {
+        insertAnnotation(cr, url, key.getDbValue(), value);
+    }
+
+    @RobocopTarget
+    @Override
+    public void insertAnnotation(final ContentResolver cr, final String url, final String key, final String value) {
+        final long creationTime = System.currentTimeMillis();
+        final ContentValues values = new ContentValues(5);
+        values.put(BrowserContract.UrlAnnotations.URL, url);
+        values.put(BrowserContract.UrlAnnotations.KEY, key);
+        values.put(BrowserContract.UrlAnnotations.VALUE, value);
+        values.put(BrowserContract.UrlAnnotations.DATE_CREATED, creationTime);
+        values.put(BrowserContract.UrlAnnotations.DATE_MODIFIED, creationTime);
+        cr.insert(urlAnnotationsTableWithProfile, values);
+    }
+
+    /**
+     * @return true if the table contains rows for the given selection.
+     */
+    private boolean hasResultsForSelection(ContentResolver cr, String selection, String[] selectionArgs) {
+        Cursor cursor = cr.query(urlAnnotationsTableWithProfile,
+                new String[] { BrowserContract.UrlAnnotations._ID },
+                selection,
+                selectionArgs,
+                null);
+        if (cursor == null) {
+            return false;
+        }
+
+        try {
+            return cursor.getCount() > 0;
+        } finally {
+            cursor.close();
+        }
+    }
+
+    private Cursor queryByKey(final ContentResolver cr, @NonNull final Key key, @Nullable final String[] projections,
+                @Nullable final String sortOrder) {
+        return cr.query(urlAnnotationsTableWithProfile,
+                projections,
+                BrowserContract.UrlAnnotations.KEY + " = ?", new String[] { key.getDbValue() },
+                sortOrder);
+    }
+
+    @Override
+    public Cursor getScreenshots(ContentResolver cr) {
+        return queryByKey(cr,
+                Key.SCREENSHOT,
+                new String[] {
+                        BrowserContract.UrlAnnotations._ID,
+                        BrowserContract.UrlAnnotations.URL,
+                        BrowserContract.UrlAnnotations.KEY,
+                        BrowserContract.UrlAnnotations.VALUE,
+                        BrowserContract.UrlAnnotations.DATE_CREATED,
+                },
+                BrowserContract.UrlAnnotations.DATE_CREATED + " DESC");
+    }
+
+    public void insertScreenshot(final ContentResolver cr, final String pageUrl, final String screenshotPath) {
+        insertAnnotation(cr, pageUrl, Key.SCREENSHOT.getDbValue(), screenshotPath);
+    }
+
+    @Override
+    public void insertReaderViewUrl(final ContentResolver cr, final String pageUrl) {
+        insertAnnotation(cr, pageUrl, Key.READER_VIEW.getDbValue(), BrowserContract.UrlAnnotations.READER_VIEW_SAVED_VALUE);
+    }
+
+    @Override
+    public void deleteReaderViewUrl(ContentResolver cr, String pageURL) {
+        deleteAnnotation(cr, pageURL, Key.READER_VIEW);
+    }
+
+    public int getAnnotationCount(ContentResolver cr, Key key) {
+        final String countColumnname = "count";
+        final Cursor c = queryByKey(cr,
+                key,
+                new String[] {
+                        "COUNT(*) AS " + countColumnname
+                },
+                null);
+
+        try {
+            if (c != null && c.moveToFirst()) {
+                return c.getInt(c.getColumnIndexOrThrow(countColumnname));
+            } else {
+                return 0;
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+            }
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/LoginsProvider.java

@@ -0,0 +1,520 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.MatrixCursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteQueryBuilder;
+import android.net.Uri;
+import android.support.annotation.NonNull;
+import android.text.TextUtils;
+import android.util.Base64;
+
+import org.mozilla.gecko.db.BrowserContract.DeletedLogins;
+import org.mozilla.gecko.db.BrowserContract.Logins;
+import org.mozilla.gecko.db.BrowserContract.LoginsDisabledHosts;
+import org.mozilla.gecko.sync.Utils;
+
+import java.io.UnsupportedEncodingException;
+import java.security.GeneralSecurityException;
+import java.util.HashMap;
+
+import javax.crypto.Cipher;
+import javax.crypto.NullCipher;
+
+import static org.mozilla.gecko.db.BrowserContract.DeletedLogins.TABLE_DELETED_LOGINS;
+import static org.mozilla.gecko.db.BrowserContract.Logins.TABLE_LOGINS;
+import static org.mozilla.gecko.db.BrowserContract.LoginsDisabledHosts.TABLE_DISABLED_HOSTS;
+
+public class LoginsProvider extends SharedBrowserDatabaseProvider {
+
+    private static final int LOGINS = 100;
+    private static final int LOGINS_ID = 101;
+    private static final int DELETED_LOGINS = 102;
+    private static final int DELETED_LOGINS_ID = 103;
+    private static final int DISABLED_HOSTS = 104;
+    private static final int DISABLED_HOSTS_HOSTNAME = 105;
+    private static final UriMatcher URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
+
+    private static final HashMap<String, String> LOGIN_PROJECTION_MAP;
+    private static final HashMap<String, String> DELETED_LOGIN_PROJECTION_MAP;
+    private static final HashMap<String, String> DISABLED_HOSTS_PROJECTION_MAP;
+
+    private static final String DEFAULT_LOGINS_SORT_ORDER = Logins.HOSTNAME + " ASC";
+    private static final String DEFAULT_DELETED_LOGINS_SORT_ORDER = DeletedLogins.TIME_DELETED + " ASC";
+    private static final String DEFAULT_DISABLED_HOSTS_SORT_ORDER = LoginsDisabledHosts.HOSTNAME + " ASC";
+    private static final String WHERE_GUID_IS_NULL = DeletedLogins.GUID + " IS NULL";
+    private static final String WHERE_GUID_IS_VALUE = DeletedLogins.GUID + " = ?";
+
+    protected static final String INDEX_LOGINS_HOSTNAME = "login_hostname_index";
+    protected static final String INDEX_LOGINS_HOSTNAME_FORM_SUBMIT_URL = "login_hostname_formSubmitURL_index";
+    protected static final String INDEX_LOGINS_HOSTNAME_HTTP_REALM = "login_hostname_httpRealm_index";
+
+    static {
+        URI_MATCHER.addURI(BrowserContract.LOGINS_AUTHORITY, "logins", LOGINS);
+        URI_MATCHER.addURI(BrowserContract.LOGINS_AUTHORITY, "logins/#", LOGINS_ID);
+        URI_MATCHER.addURI(BrowserContract.LOGINS_AUTHORITY, "deleted-logins", DELETED_LOGINS);
+        URI_MATCHER.addURI(BrowserContract.LOGINS_AUTHORITY, "deleted-logins/#", DELETED_LOGINS_ID);
+        URI_MATCHER.addURI(BrowserContract.LOGINS_AUTHORITY, "logins-disabled-hosts", DISABLED_HOSTS);
+        URI_MATCHER.addURI(BrowserContract.LOGINS_AUTHORITY, "logins-disabled-hosts/hostname/*", DISABLED_HOSTS_HOSTNAME);
+
+        LOGIN_PROJECTION_MAP = new HashMap<>();
+        LOGIN_PROJECTION_MAP.put(Logins._ID, Logins._ID);
+        LOGIN_PROJECTION_MAP.put(Logins.HOSTNAME, Logins.HOSTNAME);
+        LOGIN_PROJECTION_MAP.put(Logins.HTTP_REALM, Logins.HTTP_REALM);
+        LOGIN_PROJECTION_MAP.put(Logins.FORM_SUBMIT_URL, Logins.FORM_SUBMIT_URL);
+        LOGIN_PROJECTION_MAP.put(Logins.USERNAME_FIELD, Logins.USERNAME_FIELD);
+        LOGIN_PROJECTION_MAP.put(Logins.PASSWORD_FIELD, Logins.PASSWORD_FIELD);
+        LOGIN_PROJECTION_MAP.put(Logins.ENCRYPTED_USERNAME, Logins.ENCRYPTED_USERNAME);
+        LOGIN_PROJECTION_MAP.put(Logins.ENCRYPTED_PASSWORD, Logins.ENCRYPTED_PASSWORD);
+        LOGIN_PROJECTION_MAP.put(Logins.GUID, Logins.GUID);
+        LOGIN_PROJECTION_MAP.put(Logins.ENC_TYPE, Logins.ENC_TYPE);
+        LOGIN_PROJECTION_MAP.put(Logins.TIME_CREATED, Logins.TIME_CREATED);
+        LOGIN_PROJECTION_MAP.put(Logins.TIME_LAST_USED, Logins.TIME_LAST_USED);
+        LOGIN_PROJECTION_MAP.put(Logins.TIME_PASSWORD_CHANGED, Logins.TIME_PASSWORD_CHANGED);
+        LOGIN_PROJECTION_MAP.put(Logins.TIMES_USED, Logins.TIMES_USED);
+
+        DELETED_LOGIN_PROJECTION_MAP = new HashMap<>();
+        DELETED_LOGIN_PROJECTION_MAP.put(DeletedLogins._ID, DeletedLogins._ID);
+        DELETED_LOGIN_PROJECTION_MAP.put(DeletedLogins.GUID, DeletedLogins.GUID);
+        DELETED_LOGIN_PROJECTION_MAP.put(DeletedLogins.TIME_DELETED, DeletedLogins.TIME_DELETED);
+
+        DISABLED_HOSTS_PROJECTION_MAP = new HashMap<>();
+        DISABLED_HOSTS_PROJECTION_MAP.put(LoginsDisabledHosts._ID, LoginsDisabledHosts._ID);
+        DISABLED_HOSTS_PROJECTION_MAP.put(LoginsDisabledHosts.HOSTNAME, LoginsDisabledHosts.HOSTNAME);
+    }
+
+    private static String projectColumn(String table, String column) {
+        return table + "." + column;
+    }
+
+    private static String selectColumn(String table, String column) {
+        return projectColumn(table, column) + " = ?";
+    }
+
+    @Override
+    protected Uri insertInTransaction(Uri uri, ContentValues values) {
+        trace("Calling insert in transaction on URI: " + uri);
+
+        final int match = URI_MATCHER.match(uri);
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        final long id;
+        String guid;
+
+        setupDefaultValues(values, uri);
+        switch (match) {
+            case LOGINS:
+                removeDeletedLoginsByGUIDInTransaction(values, db);
+                // Encrypt sensitive data.
+                encryptContentValueFields(values);
+                guid = values.getAsString(Logins.GUID);
+                debug("Inserting login in database with GUID: " + guid);
+                id = db.insertOrThrow(TABLE_LOGINS, Logins.GUID, values);
+                break;
+
+            case DELETED_LOGINS:
+                guid = values.getAsString(DeletedLogins.GUID);
+                debug("Inserting deleted-login in database with GUID: " + guid);
+                id = db.insertOrThrow(TABLE_DELETED_LOGINS, DeletedLogins.GUID, values);
+                break;
+
+            case DISABLED_HOSTS:
+                String hostname = values.getAsString(LoginsDisabledHosts.HOSTNAME);
+                debug("Inserting disabled-host in database with hostname: " + hostname);
+                id = db.insertOrThrow(TABLE_DISABLED_HOSTS, LoginsDisabledHosts.HOSTNAME, values);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown insert URI " + uri);
+        }
+
+        debug("Inserted ID in database: " + id);
+
+        if (id >= 0) {
+            return ContentUris.withAppendedId(uri, id);
+        }
+
+        return null;
+    }
+
+    @Override
+    @SuppressWarnings("fallthrough")
+    protected int deleteInTransaction(Uri uri, String selection, String[] selectionArgs) {
+        trace("Calling delete in transaction on URI: " + uri);
+
+        final int match = URI_MATCHER.match(uri);
+        final String table;
+        final SQLiteDatabase db = getWritableDatabase(uri);
+
+        beginWrite(db);
+        switch (match) {
+            case LOGINS_ID:
+                trace("Delete on LOGINS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_LOGINS, Logins._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[]{Long.toString(ContentUris.parseId(uri))});
+                // Store the deleted client in deleted-logins table.
+                final String guid = getLoginGUIDByID(selection, selectionArgs, db);
+                if (guid == null) {
+                    // No matching logins found for the id.
+                    return 0;
+                }
+                boolean isInsertSuccessful = storeDeletedLoginForGUIDInTransaction(guid, db);
+                if (!isInsertSuccessful) {
+                    // Failed to insert into deleted-logins, return early.
+                    return 0;
+                }
+            // fall through
+            case LOGINS:
+                trace("Delete on LOGINS: " + uri);
+                table = TABLE_LOGINS;
+                break;
+
+            case DELETED_LOGINS_ID:
+                trace("Delete on DELETED_LOGINS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_DELETED_LOGINS, DeletedLogins._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[]{Long.toString(ContentUris.parseId(uri))});
+            // fall through
+            case DELETED_LOGINS:
+                trace("Delete on DELETED_LOGINS_ID: " + uri);
+                table = TABLE_DELETED_LOGINS;
+                break;
+
+            case DISABLED_HOSTS_HOSTNAME:
+                trace("Delete on DISABLED_HOSTS_HOSTNAME: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_DISABLED_HOSTS, LoginsDisabledHosts.HOSTNAME));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[]{uri.getLastPathSegment()});
+            // fall through
+            case DISABLED_HOSTS:
+                trace("Delete on DISABLED_HOSTS: " + uri);
+                table = TABLE_DISABLED_HOSTS;
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown delete URI " + uri);
+        }
+
+        debug("Deleting " + table + " for URI: " + uri);
+        return db.delete(table, selection, selectionArgs);
+    }
+
+    @Override
+    @SuppressWarnings("fallthrough")
+    protected int updateInTransaction(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        trace("Calling update in transaction on URI: " + uri);
+
+        final int match = URI_MATCHER.match(uri);
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        final String table;
+
+        beginWrite(db);
+        switch (match) {
+            case LOGINS_ID:
+                trace("Update on LOGINS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_LOGINS, Logins._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[]{Long.toString(ContentUris.parseId(uri))});
+
+            case LOGINS:
+                trace("Update on LOGINS: " + uri);
+                table = TABLE_LOGINS;
+                // Encrypt sensitive data.
+                encryptContentValueFields(values);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown update URI " + uri);
+        }
+
+        trace("Updating " + table + " on URI: " + uri);
+        return db.update(table, values, selection, selectionArgs);
+
+    }
+
+    @Override
+    @SuppressWarnings("fallthrough")
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
+        trace("Calling query on URI: " + uri);
+
+        final SQLiteDatabase db = getReadableDatabase(uri);
+        final int match = URI_MATCHER.match(uri);
+        final String groupBy = null;
+        final SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
+        final String limit = uri.getQueryParameter(BrowserContract.PARAM_LIMIT);
+
+        switch (match) {
+            case LOGINS_ID:
+                trace("Query is on LOGINS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_LOGINS, Logins._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+
+            // fall through
+            case LOGINS:
+                trace("Query is on LOGINS: " + uri);
+                if (TextUtils.isEmpty(sortOrder)) {
+                    sortOrder = DEFAULT_LOGINS_SORT_ORDER;
+                } else {
+                    debug("Using sort order " + sortOrder + ".");
+                }
+
+                qb.setProjectionMap(LOGIN_PROJECTION_MAP);
+                qb.setTables(TABLE_LOGINS);
+                break;
+
+            case DELETED_LOGINS_ID:
+                trace("Query is on DELETED_LOGINS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_DELETED_LOGINS, DeletedLogins._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+
+            // fall through
+            case DELETED_LOGINS:
+                trace("Query is on DELETED_LOGINS: " + uri);
+                if (TextUtils.isEmpty(sortOrder)) {
+                    sortOrder = DEFAULT_DELETED_LOGINS_SORT_ORDER;
+                } else {
+                    debug("Using sort order " + sortOrder + ".");
+                }
+
+                qb.setProjectionMap(DELETED_LOGIN_PROJECTION_MAP);
+                qb.setTables(TABLE_DELETED_LOGINS);
+                break;
+
+            case DISABLED_HOSTS_HOSTNAME:
+                trace("Query is on DISABLED_HOSTS_HOSTNAME: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_DISABLED_HOSTS, LoginsDisabledHosts.HOSTNAME));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { uri.getLastPathSegment() });
+
+            // fall through
+            case DISABLED_HOSTS:
+                trace("Query is on DISABLED_HOSTS: " + uri);
+                if (TextUtils.isEmpty(sortOrder)) {
+                    sortOrder = DEFAULT_DISABLED_HOSTS_SORT_ORDER;
+                } else {
+                    debug("Using sort order " + sortOrder + ".");
+                }
+
+                qb.setProjectionMap(DISABLED_HOSTS_PROJECTION_MAP);
+                qb.setTables(TABLE_DISABLED_HOSTS);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown query URI " + uri);
+        }
+
+        trace("Running built query.");
+        Cursor cursor = qb.query(db, projection, selection, selectionArgs, groupBy, null, sortOrder, limit);
+        // If decryptManyCursorRows does not return the original cursor, it closes it, so there's
+        // no need to close here.
+        cursor = decryptManyCursorRows(cursor);
+        cursor.setNotificationUri(getContext().getContentResolver(), BrowserContract.LOGINS_AUTHORITY_URI);
+        return cursor;
+    }
+
+    @Override
+    public String getType(@NonNull Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+
+        switch (match) {
+            case LOGINS:
+                return Logins.CONTENT_TYPE;
+
+            case LOGINS_ID:
+                return Logins.CONTENT_ITEM_TYPE;
+
+            case DELETED_LOGINS:
+                return DeletedLogins.CONTENT_TYPE;
+
+            case DELETED_LOGINS_ID:
+                return DeletedLogins.CONTENT_ITEM_TYPE;
+
+            case DISABLED_HOSTS:
+                return LoginsDisabledHosts.CONTENT_TYPE;
+
+            case DISABLED_HOSTS_HOSTNAME:
+                return LoginsDisabledHosts.CONTENT_ITEM_TYPE;
+
+            default:
+                throw new UnsupportedOperationException("Unknown type " + uri);
+        }
+    }
+
+    /**
+     * Caller is responsible for invoking this method inside a transaction.
+     */
+    private String getLoginGUIDByID(final String selection, final String[] selectionArgs, final SQLiteDatabase db) {
+        final Cursor cursor = db.query(Logins.TABLE_LOGINS, new String[]{Logins.GUID}, selection, selectionArgs, null, null, DEFAULT_LOGINS_SORT_ORDER);
+        try {
+            if (!cursor.moveToFirst()) {
+                return null;
+            }
+            return cursor.getString(cursor.getColumnIndexOrThrow(Logins.GUID));
+        } finally {
+            cursor.close();
+        }
+    }
+
+    /**
+     * Caller is responsible for invoking this method inside a transaction.
+     */
+    private boolean storeDeletedLoginForGUIDInTransaction(final String guid, final SQLiteDatabase db) {
+        if (guid == null) {
+            return false;
+        }
+        final ContentValues values = new ContentValues();
+        values.put(DeletedLogins.GUID, guid);
+        values.put(DeletedLogins.TIME_DELETED, System.currentTimeMillis());
+        return db.insert(TABLE_DELETED_LOGINS, DeletedLogins.GUID, values) > 0;
+    }
+
+    /**
+     * Caller is responsible for invoking this method inside a transaction.
+     */
+    private void removeDeletedLoginsByGUIDInTransaction(ContentValues values, SQLiteDatabase db) {
+        if (values.containsKey(Logins.GUID)) {
+            final String guid = values.getAsString(Logins.GUID);
+            if (guid == null) {
+                db.delete(TABLE_DELETED_LOGINS, WHERE_GUID_IS_NULL, null);
+            } else {
+                String[] args = new String[]{guid};
+                db.delete(TABLE_DELETED_LOGINS, WHERE_GUID_IS_VALUE, args);
+            }
+        }
+    }
+
+    private void setupDefaultValues(ContentValues values, Uri uri) throws IllegalArgumentException {
+        final int match = URI_MATCHER.match(uri);
+        final long now = System.currentTimeMillis();
+        switch (match) {
+            case DELETED_LOGINS:
+                values.put(DeletedLogins.TIME_DELETED, now);
+                // deleted-logins must contain a guid
+                if (!values.containsKey(DeletedLogins.GUID)) {
+                    throw new IllegalArgumentException("Must provide GUID for deleted-login");
+                }
+                break;
+
+            case LOGINS:
+                values.put(Logins.TIME_CREATED, now);
+                // Generate GUID for new login. Don't override specified GUIDs.
+                if (!values.containsKey(Logins.GUID)) {
+                    final String guid = Utils.generateGuid();
+                    values.put(Logins.GUID, guid);
+                }
+                // The database happily accepts strings for long values; this just lets us re-use
+                // the existing helper method.
+                String nowString = Long.toString(now);
+                DBUtils.replaceKey(values, null, Logins.HTTP_REALM, null);
+                DBUtils.replaceKey(values, null, Logins.FORM_SUBMIT_URL, null);
+                DBUtils.replaceKey(values, null, Logins.ENC_TYPE, "0");
+                DBUtils.replaceKey(values, null, Logins.TIME_LAST_USED, nowString);
+                DBUtils.replaceKey(values, null, Logins.TIME_PASSWORD_CHANGED, nowString);
+                DBUtils.replaceKey(values, null, Logins.TIMES_USED, "0");
+                break;
+
+            case DISABLED_HOSTS:
+                if (!values.containsKey(LoginsDisabledHosts.HOSTNAME)) {
+                    throw new IllegalArgumentException("Must provide hostname for disabled-host");
+                }
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown URI in setupDefaultValues " + uri);
+        }
+    }
+
+    private void encryptContentValueFields(final ContentValues values) {
+        if (values.containsKey(Logins.ENCRYPTED_PASSWORD)) {
+            final String res = encrypt(values.getAsString(Logins.ENCRYPTED_PASSWORD));
+            values.put(Logins.ENCRYPTED_PASSWORD, res);
+        }
+
+        if (values.containsKey(Logins.ENCRYPTED_USERNAME)) {
+            final String res = encrypt(values.getAsString(Logins.ENCRYPTED_USERNAME));
+            values.put(Logins.ENCRYPTED_USERNAME, res);
+        }
+    }
+
+    /**
+     * Replace each password and username encrypted ciphertext with its equivalent decrypted
+     * plaintext in the given cursor.
+     * <p/>
+     * The encryption algorithm used to protect logins is unspecified; and further, a consumer of
+     * consumers should never have access to encrypted ciphertext.
+     *
+     * @param cursor containing at least one of password and username encrypted ciphertexts.
+     * @return a new {@link Cursor} with password and username decrypted plaintexts.
+     */
+    private Cursor decryptManyCursorRows(final Cursor cursor) {
+        final int passwordIndex = cursor.getColumnIndex(Logins.ENCRYPTED_PASSWORD);
+        final int usernameIndex = cursor.getColumnIndex(Logins.ENCRYPTED_USERNAME);
+
+        if (passwordIndex == -1 && usernameIndex == -1) {
+            return cursor;
+        }
+
+        // Special case, decrypt the encrypted username or password before returning the cursor.
+        final MatrixCursor newCursor = new MatrixCursor(cursor.getColumnNames(), cursor.getColumnCount());
+        try {
+            for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {
+                final ContentValues values = new ContentValues();
+                DatabaseUtils.cursorRowToContentValues(cursor, values);
+
+                if (passwordIndex > -1) {
+                    String decrypted = decrypt(values.getAsString(Logins.ENCRYPTED_PASSWORD));
+                    values.put(Logins.ENCRYPTED_PASSWORD, decrypted);
+                }
+
+                if (usernameIndex > -1) {
+                    String decrypted = decrypt(values.getAsString(Logins.ENCRYPTED_USERNAME));
+                    values.put(Logins.ENCRYPTED_USERNAME, decrypted);
+                }
+
+                final MatrixCursor.RowBuilder rowBuilder = newCursor.newRow();
+                for (String key : cursor.getColumnNames()) {
+                    rowBuilder.add(values.get(key));
+                }
+            }
+        } finally {
+            // Close the old cursor before returning the new one.
+            cursor.close();
+        }
+
+        return newCursor;
+    }
+
+    private String encrypt(@NonNull String initialValue) {
+        try {
+            final Cipher cipher = getCipher(Cipher.ENCRYPT_MODE);
+            return Base64.encodeToString(cipher.doFinal(initialValue.getBytes("UTF-8")), Base64.URL_SAFE);
+        } catch (Exception e) {
+            debug("encryption failed : " + e);
+            throw new IllegalStateException("Logins encryption failed", e);
+        }
+    }
+
+    private String decrypt(@NonNull String initialValue) {
+        try {
+            final Cipher cipher = getCipher(Cipher.DECRYPT_MODE);
+            return new String(cipher.doFinal(Base64.decode(initialValue.getBytes("UTF-8"), Base64.URL_SAFE)));
+        } catch (Exception e) {
+            debug("Decryption failed : " + e);
+            throw new IllegalStateException("Logins decryption failed", e);
+        }
+    }
+
+    private Cipher getCipher(int mode) throws UnsupportedEncodingException, GeneralSecurityException {
+        return new NullCipher();
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/PasswordsProvider.java

@@ -0,0 +1,348 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.util.HashMap;
+
+import org.mozilla.gecko.CrashHandler;
+import org.mozilla.gecko.GeckoApp;
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.GeckoMessageReceiver;
+import org.mozilla.gecko.NSSBridge;
+import org.mozilla.gecko.db.BrowserContract.DeletedPasswords;
+import org.mozilla.gecko.db.BrowserContract.GeckoDisabledHosts;
+import org.mozilla.gecko.db.BrowserContract.Passwords;
+import org.mozilla.gecko.mozglue.GeckoLoader;
+import org.mozilla.gecko.sqlite.MatrixBlobCursor;
+import org.mozilla.gecko.sqlite.SQLiteBridge;
+import org.mozilla.gecko.sync.Utils;
+
+import android.content.ContentValues;
+import android.content.Intent;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+public class PasswordsProvider extends SQLiteBridgeContentProvider {
+    static final String TABLE_PASSWORDS = "moz_logins";
+    static final String TABLE_DELETED_PASSWORDS = "moz_deleted_logins";
+    static final String TABLE_DISABLED_HOSTS = "moz_disabledHosts";
+
+    private static final String TELEMETRY_TAG = "SQLITEBRIDGE_PROVIDER_PASSWORDS";
+
+    private static final int PASSWORDS = 100;
+    private static final int DELETED_PASSWORDS = 101;
+    private static final int DISABLED_HOSTS = 102;
+
+    static final String DEFAULT_PASSWORDS_SORT_ORDER = Passwords.HOSTNAME + " ASC";
+    static final String DEFAULT_DELETED_PASSWORDS_SORT_ORDER = DeletedPasswords.TIME_DELETED + " ASC";
+
+    private static final UriMatcher URI_MATCHER;
+
+    private static final HashMap<String, String> PASSWORDS_PROJECTION_MAP;
+    private static final HashMap<String, String> DELETED_PASSWORDS_PROJECTION_MAP;
+    private static final HashMap<String, String> DISABLED_HOSTS_PROJECTION_MAP;
+
+    // this should be kept in sync with the version in toolkit/components/passwordmgr/storage-mozStorage.js
+    private static final int DB_VERSION = 6;
+    private static final String DB_FILENAME = "signons.sqlite";
+    private static final String WHERE_GUID_IS_NULL = BrowserContract.DeletedPasswords.GUID + " IS NULL";
+    private static final String WHERE_GUID_IS_VALUE = BrowserContract.DeletedPasswords.GUID + " = ?";
+
+    private static final String LOG_TAG = "GeckoPasswordsProvider";
+
+    private CrashHandler mCrashHandler;
+
+    static {
+        URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
+
+        // content://org.mozilla.gecko.providers.browser/passwords/#
+        URI_MATCHER.addURI(BrowserContract.PASSWORDS_AUTHORITY, "passwords", PASSWORDS);
+
+        PASSWORDS_PROJECTION_MAP = new HashMap<String, String>();
+        PASSWORDS_PROJECTION_MAP.put(Passwords.ID, Passwords.ID);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.HOSTNAME, Passwords.HOSTNAME);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.HTTP_REALM, Passwords.HTTP_REALM);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.FORM_SUBMIT_URL, Passwords.FORM_SUBMIT_URL);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.USERNAME_FIELD, Passwords.USERNAME_FIELD);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.PASSWORD_FIELD, Passwords.PASSWORD_FIELD);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.ENCRYPTED_USERNAME, Passwords.ENCRYPTED_USERNAME);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.ENCRYPTED_PASSWORD, Passwords.ENCRYPTED_PASSWORD);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.GUID, Passwords.GUID);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.ENC_TYPE, Passwords.ENC_TYPE);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.TIME_CREATED, Passwords.TIME_CREATED);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.TIME_LAST_USED, Passwords.TIME_LAST_USED);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.TIME_PASSWORD_CHANGED, Passwords.TIME_PASSWORD_CHANGED);
+        PASSWORDS_PROJECTION_MAP.put(Passwords.TIMES_USED, Passwords.TIMES_USED);
+
+        URI_MATCHER.addURI(BrowserContract.PASSWORDS_AUTHORITY, "deleted-passwords", DELETED_PASSWORDS);
+
+        DELETED_PASSWORDS_PROJECTION_MAP = new HashMap<String, String>();
+        DELETED_PASSWORDS_PROJECTION_MAP.put(DeletedPasswords.ID, DeletedPasswords.ID);
+        DELETED_PASSWORDS_PROJECTION_MAP.put(DeletedPasswords.GUID, DeletedPasswords.GUID);
+        DELETED_PASSWORDS_PROJECTION_MAP.put(DeletedPasswords.TIME_DELETED, DeletedPasswords.TIME_DELETED);
+
+        URI_MATCHER.addURI(BrowserContract.PASSWORDS_AUTHORITY, "disabled-hosts", DISABLED_HOSTS);
+
+        DISABLED_HOSTS_PROJECTION_MAP = new HashMap<String, String>();
+        DISABLED_HOSTS_PROJECTION_MAP.put(GeckoDisabledHosts.HOSTNAME, GeckoDisabledHosts.HOSTNAME);
+    }
+
+    public PasswordsProvider() {
+        super(LOG_TAG);
+    }
+
+    @Override
+    public boolean onCreate() {
+        mCrashHandler = CrashHandler.createDefaultCrashHandler(getContext());
+
+        // We don't use .loadMozGlue because we're in a different process,
+        // and we just want to reuse code rather than use the loader lock etc.
+        GeckoLoader.doLoadLibrary(getContext(), "mozglue");
+        return super.onCreate();
+    }
+
+    @Override
+    public void shutdown() {
+        super.shutdown();
+
+        if (mCrashHandler != null) {
+            mCrashHandler.unregister();
+            mCrashHandler = null;
+        }
+    }
+
+    @Override
+    protected String getDBName() {
+        return DB_FILENAME;
+    }
+
+    @Override
+    protected String getTelemetryPrefix() {
+        return TELEMETRY_TAG;
+    }
+
+    @Override
+    protected int getDBVersion() {
+        return DB_VERSION;
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+
+        switch (match) {
+            case PASSWORDS:
+                return Passwords.CONTENT_TYPE;
+
+            case DELETED_PASSWORDS:
+                return DeletedPasswords.CONTENT_TYPE;
+
+            case DISABLED_HOSTS:
+                return GeckoDisabledHosts.CONTENT_TYPE;
+
+            default:
+                throw new UnsupportedOperationException("Unknown type " + uri);
+        }
+    }
+
+    @Override
+    public String getTable(Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+        switch (match) {
+            case DELETED_PASSWORDS:
+                return TABLE_DELETED_PASSWORDS;
+
+            case PASSWORDS:
+                return TABLE_PASSWORDS;
+
+            case DISABLED_HOSTS:
+                return TABLE_DISABLED_HOSTS;
+
+            default:
+                throw new UnsupportedOperationException("Unknown table " + uri);
+        }
+    }
+
+    @Override
+    public String getSortOrder(Uri uri, String aRequested) {
+        if (!TextUtils.isEmpty(aRequested)) {
+            return aRequested;
+        }
+
+        final int match = URI_MATCHER.match(uri);
+        switch (match) {
+            case DELETED_PASSWORDS:
+                return DEFAULT_DELETED_PASSWORDS_SORT_ORDER;
+
+            case PASSWORDS:
+                return DEFAULT_PASSWORDS_SORT_ORDER;
+
+            case DISABLED_HOSTS:
+                return null;
+
+            default:
+                throw new UnsupportedOperationException("Unknown URI " + uri);
+        }
+    }
+
+    @Override
+    public void setupDefaults(Uri uri, ContentValues values)
+            throws IllegalArgumentException {
+        int match = URI_MATCHER.match(uri);
+        long now = System.currentTimeMillis();
+        switch (match) {
+            case DELETED_PASSWORDS:
+                values.put(DeletedPasswords.TIME_DELETED, now);
+
+                // Deleted passwords must contain a guid
+                if (!values.containsKey(Passwords.GUID)) {
+                    throw new IllegalArgumentException("Must provide a GUID for a deleted password");
+                }
+                break;
+
+            case PASSWORDS:
+                values.put(Passwords.TIME_CREATED, now);
+
+                // Generate GUID for new password. Don't override specified GUIDs.
+                if (!values.containsKey(Passwords.GUID)) {
+                    String guid = Utils.generateGuid();
+                    values.put(Passwords.GUID, guid);
+                }
+                String nowString = Long.toString(now);
+                DBUtils.replaceKey(values, null, Passwords.HOSTNAME, "");
+                DBUtils.replaceKey(values, null, Passwords.HTTP_REALM, "");
+                DBUtils.replaceKey(values, null, Passwords.FORM_SUBMIT_URL, "");
+                DBUtils.replaceKey(values, null, Passwords.USERNAME_FIELD, "");
+                DBUtils.replaceKey(values, null, Passwords.PASSWORD_FIELD, "");
+                DBUtils.replaceKey(values, null, Passwords.ENCRYPTED_USERNAME, "");
+                DBUtils.replaceKey(values, null, Passwords.ENCRYPTED_PASSWORD, "");
+                DBUtils.replaceKey(values, null, Passwords.ENC_TYPE, "0");
+                DBUtils.replaceKey(values, null, Passwords.TIME_LAST_USED, nowString);
+                DBUtils.replaceKey(values, null, Passwords.TIME_PASSWORD_CHANGED, nowString);
+                DBUtils.replaceKey(values, null, Passwords.TIMES_USED, "0");
+                break;
+
+            case DISABLED_HOSTS:
+                if (!values.containsKey(GeckoDisabledHosts.HOSTNAME)) {
+                    throw new IllegalArgumentException("Must provide a hostname for a disabled host");
+                }
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown URI " + uri);
+        }
+    }
+
+    @Override
+    public void initGecko() {
+        // We're not in the main process.  The receiver of this Intent can
+        // communicate with Gecko in the main process.
+        Intent initIntent = new Intent(getContext(), GeckoMessageReceiver.class);
+        initIntent.setAction(GeckoApp.ACTION_INIT_PW);
+        mContext.sendBroadcast(initIntent);
+    }
+
+    private String doCrypto(String initialValue, Uri uri, Boolean encrypt) {
+        String profilePath = null;
+        if (uri != null) {
+            profilePath = uri.getQueryParameter(BrowserContract.PARAM_PROFILE_PATH);
+        }
+
+        String result = "";
+        try {
+            if (encrypt) {
+                if (profilePath != null) {
+                    result = NSSBridge.encrypt(mContext, profilePath, initialValue);
+                } else {
+                    result = NSSBridge.encrypt(mContext, initialValue);
+                }
+            } else {
+                if (profilePath != null) {
+                    result = NSSBridge.decrypt(mContext, profilePath, initialValue);
+                } else {
+                    result = NSSBridge.decrypt(mContext, initialValue);
+                }
+            }
+        } catch (Exception ex) {
+            Log.e(LOG_TAG, "Error in NSSBridge");
+            throw new RuntimeException(ex);
+        }
+        return result;
+    }
+
+    @Override
+    public void onPreInsert(ContentValues values, Uri uri, SQLiteBridge db) {
+        if (values.containsKey(Passwords.GUID)) {
+            String guid = values.getAsString(Passwords.GUID);
+            if (guid == null) {
+                db.delete(TABLE_DELETED_PASSWORDS, WHERE_GUID_IS_NULL, null);
+                return;
+            }
+            String[] args = new String[] { guid };
+            db.delete(TABLE_DELETED_PASSWORDS, WHERE_GUID_IS_VALUE, args);
+        }
+
+        if (values.containsKey(Passwords.ENCRYPTED_PASSWORD)) {
+            String res = doCrypto(values.getAsString(Passwords.ENCRYPTED_PASSWORD), uri, true);
+            values.put(Passwords.ENCRYPTED_PASSWORD, res);
+            values.put(Passwords.ENC_TYPE, Passwords.ENCTYPE_SDR);
+        }
+
+        if (values.containsKey(Passwords.ENCRYPTED_USERNAME)) {
+            String res = doCrypto(values.getAsString(Passwords.ENCRYPTED_USERNAME), uri, true);
+            values.put(Passwords.ENCRYPTED_USERNAME, res);
+            values.put(Passwords.ENC_TYPE, Passwords.ENCTYPE_SDR);
+        }
+    }
+
+    @Override
+    public void onPreUpdate(ContentValues values, Uri uri, SQLiteBridge db) {
+        if (values.containsKey(Passwords.ENCRYPTED_PASSWORD)) {
+            String res = doCrypto(values.getAsString(Passwords.ENCRYPTED_PASSWORD), uri, true);
+            values.put(Passwords.ENCRYPTED_PASSWORD, res);
+            values.put(Passwords.ENC_TYPE, Passwords.ENCTYPE_SDR);
+        }
+
+        if (values.containsKey(Passwords.ENCRYPTED_USERNAME)) {
+            String res = doCrypto(values.getAsString(Passwords.ENCRYPTED_USERNAME), uri, true);
+            values.put(Passwords.ENCRYPTED_USERNAME, res);
+            values.put(Passwords.ENC_TYPE, Passwords.ENCTYPE_SDR);
+        }
+    }
+
+    @Override
+    public void onPostQuery(Cursor cursor, Uri uri, SQLiteBridge db) {
+        int passwordIndex = -1;
+        int usernameIndex = -1;
+        String profilePath = null;
+
+        try {
+            passwordIndex = cursor.getColumnIndexOrThrow(Passwords.ENCRYPTED_PASSWORD);
+        } catch (Exception ex) { }
+        try {
+            usernameIndex = cursor.getColumnIndexOrThrow(Passwords.ENCRYPTED_USERNAME);
+        } catch (Exception ex) { }
+
+        if (passwordIndex > -1 || usernameIndex > -1) {
+            MatrixBlobCursor m = (MatrixBlobCursor)cursor;
+            if (cursor.moveToFirst()) {
+                do {
+                    if (passwordIndex > -1) {
+                        String decrypted = doCrypto(cursor.getString(passwordIndex), uri, false);;
+                        m.set(passwordIndex, decrypted);
+                    }
+
+                    if (usernameIndex > -1) {
+                        String decrypted = doCrypto(cursor.getString(usernameIndex), uri, false);
+                        m.set(usernameIndex, decrypted);
+                    }
+                } while (cursor.moveToNext());
+            }
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/PerProfileDatabaseProvider.java

@@ -0,0 +1,55 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.AppConstants.Versions;
+import org.mozilla.gecko.db.PerProfileDatabases.DatabaseHelperFactory;
+
+import android.content.Context;
+import android.database.sqlite.SQLiteOpenHelper;
+
+/**
+ * Abstract class containing methods needed to make a SQLite-based content
+ * provider with a database helper of type T, where one database helper is
+ * held per profile.
+ */
+public abstract class PerProfileDatabaseProvider<T extends SQLiteOpenHelper> extends AbstractPerProfileDatabaseProvider {
+    private PerProfileDatabases<T> databases;
+
+    @Override
+    protected PerProfileDatabases<T> getDatabases() {
+        return databases;
+    }
+
+    protected abstract String getDatabaseName();
+
+    /**
+     * Creates and returns an instance of the appropriate DB helper.
+     *
+     * @param  context       to use to create the database helper
+     * @param  databasePath  path to the DB file
+     * @return               instance of the database helper
+     */
+    protected abstract T createDatabaseHelper(Context context, String databasePath);
+
+    @Override
+    public boolean onCreate() {
+        synchronized (this) {
+            databases = new PerProfileDatabases<T>(
+                getContext(), getDatabaseName(), new DatabaseHelperFactory<T>() {
+                    @Override
+                    public T makeDatabaseHelper(Context context, String databasePath) {
+                        final T helper = createDatabaseHelper(context, databasePath);
+                        if (Versions.feature16Plus) {
+                            helper.setWriteAheadLoggingEnabled(true);
+                        }
+                        return helper;
+                    }
+                });
+        }
+
+        return true;
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/PerProfileDatabases.java

@@ -0,0 +1,94 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.io.File;
+import java.util.HashMap;
+
+import org.mozilla.gecko.GeckoProfile;
+
+import android.content.Context;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.text.TextUtils;
+
+/**
+ * Manages a set of per-profile database storage helpers.
+ */
+public class PerProfileDatabases<T extends SQLiteOpenHelper> {
+
+    private final HashMap<String, T> mStorages = new HashMap<String, T>();
+
+    private final Context mContext;
+    private final String mDatabaseName;
+    private final DatabaseHelperFactory<T> mHelperFactory;
+
+    // Only used during tests.
+    public void shutdown() {
+        synchronized (this) {
+            for (T t : mStorages.values()) {
+                try {
+                    t.close();
+                } catch (Throwable e) {
+                    // Never mind.
+                }
+            }
+        }
+    }
+
+    public interface DatabaseHelperFactory<T> {
+        public T makeDatabaseHelper(Context context, String databasePath);
+    }
+
+    public PerProfileDatabases(final Context context, final String databaseName, final DatabaseHelperFactory<T> helperFactory) {
+        mContext = context;
+        mDatabaseName = databaseName;
+        mHelperFactory = helperFactory;
+    }
+
+    public String getDatabasePathForProfile(String profile) {
+        final File profileDir = GeckoProfile.get(mContext, profile).getDir();
+        if (profileDir == null) {
+            return null;
+        }
+
+        return new File(profileDir, mDatabaseName).getAbsolutePath();
+    }
+
+    public T getDatabaseHelperForProfile(String profile) {
+        return getDatabaseHelperForProfile(profile, false);
+    }
+
+    public T getDatabaseHelperForProfile(String profile, boolean isTest) {
+        // Always fall back to default profile if none has been provided.
+        if (profile == null) {
+            profile = GeckoProfile.get(mContext).getName();
+        }
+
+        synchronized (this) {
+            if (mStorages.containsKey(profile)) {
+                return mStorages.get(profile);
+            }
+
+            final String databasePath = isTest ? mDatabaseName : getDatabasePathForProfile(profile);
+            if (databasePath == null) {
+                throw new IllegalStateException("Database path is null for profile: " + profile);
+            }
+
+            final T helper = mHelperFactory.makeDatabaseHelper(mContext, databasePath);
+            DBUtils.ensureDatabaseIsNotLocked(helper, databasePath);
+
+            mStorages.put(profile, helper);
+            return helper;
+        }
+    }
+
+    public synchronized void shrinkMemory() {
+        for (T t : mStorages.values()) {
+            final SQLiteDatabase db = t.getWritableDatabase();
+            db.execSQL("PRAGMA shrink_memory");
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/RemoteClient.java

@@ -0,0 +1,69 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.util.ArrayList;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * A thin representation of a remote client.
+ * <p>
+ * We use the hash of the client's GUID as the ID elsewhere.
+ */
+public class RemoteClient implements Parcelable {
+    public final String guid;
+    public final String name;
+    public final long lastModified;
+    public final String deviceType;
+    public final ArrayList<RemoteTab> tabs;
+
+    public RemoteClient(String guid, String name, long lastModified, String deviceType) {
+        this.guid = guid;
+        this.name = name;
+        this.lastModified = lastModified;
+        this.deviceType = deviceType;
+        this.tabs = new ArrayList<>();
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel parcel, int flags) {
+        parcel.writeString(guid);
+        parcel.writeString(name);
+        parcel.writeLong(lastModified);
+        parcel.writeString(deviceType);
+        parcel.writeTypedList(tabs);
+    }
+
+    public static final Creator<RemoteClient> CREATOR = new Creator<RemoteClient>() {
+        @Override
+        public RemoteClient createFromParcel(final Parcel source) {
+            final String guid = source.readString();
+            final String name = source.readString();
+            final long lastModified = source.readLong();
+            final String deviceType = source.readString();
+
+            final RemoteClient client = new RemoteClient(guid, name, lastModified, deviceType);
+            source.readTypedList(client.tabs, RemoteTab.CREATOR);
+
+            return client;
+        }
+
+        @Override
+        public RemoteClient[] newArray(final int size) {
+            return new RemoteClient[size];
+        }
+    };
+
+    public boolean isDesktop() {
+        return "desktop".equals(deviceType);
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/RemoteTab.java

@@ -0,0 +1,90 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * A thin representation of a remote tab.
+ * <p>
+ * These are generated functions.
+ */
+public class RemoteTab implements Parcelable {
+    public final String title;
+    public final String url;
+    public final long lastUsed;
+
+    public RemoteTab(String title, String url, long lastUsed) {
+        this.title = title;
+        this.url = url;
+        this.lastUsed = lastUsed;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel parcel, int flags) {
+        parcel.writeString(title);
+        parcel.writeString(url);
+        parcel.writeLong(lastUsed);
+    }
+
+    public static final Creator<RemoteTab> CREATOR = new Creator<RemoteTab>() {
+        @Override
+        public RemoteTab createFromParcel(final Parcel source) {
+            final String title = source.readString();
+            final String url = source.readString();
+            final long lastUsed = source.readLong();
+            return new RemoteTab(title, url, lastUsed);
+        }
+
+        @Override
+        public RemoteTab[] newArray(final int size) {
+            return new RemoteTab[size];
+        }
+    };
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((title == null) ? 0 : title.hashCode());
+        result = prime * result + ((url == null) ? 0 : url.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        RemoteTab other = (RemoteTab) obj;
+        if (title == null) {
+            if (other.title != null) {
+                return false;
+            }
+        } else if (!title.equals(other.title)) {
+            return false;
+        }
+        if (url == null) {
+            if (other.url != null) {
+                return false;
+            }
+        } else if (!url.equals(other.url)) {
+            return false;
+        }
+        return true;
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/SQLiteBridgeContentProvider.java

@@ -0,0 +1,471 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.io.File;
+import java.util.HashMap;
+
+import org.mozilla.gecko.AppConstants;
+import org.mozilla.gecko.GeckoProfile;
+import org.mozilla.gecko.GeckoThread;
+import org.mozilla.gecko.Telemetry;
+import org.mozilla.gecko.mozglue.GeckoLoader;
+import org.mozilla.gecko.sqlite.SQLiteBridge;
+import org.mozilla.gecko.sqlite.SQLiteBridgeException;
+
+import android.content.ContentProvider;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+/*
+ * Provides a basic ContentProvider that sets up and sends queries through
+ * SQLiteBridge. Content providers should extend this by setting the appropriate
+ * table and version numbers in onCreate, and implementing the abstract methods:
+ *
+ *  public abstract String getTable(Uri uri);
+ *  public abstract String getSortOrder(Uri uri, String aRequested);
+ *  public abstract void setupDefaults(Uri uri, ContentValues values);
+ *  public abstract void initGecko();
+ */
+
+public abstract class SQLiteBridgeContentProvider extends ContentProvider {
+    private static final String ERROR_MESSAGE_DATABASE_IS_LOCKED = "Can't step statement: (5) database is locked";
+
+    private HashMap<String, SQLiteBridge> mDatabasePerProfile;
+    protected Context mContext;
+    private final String mLogTag;
+
+    protected SQLiteBridgeContentProvider(String logTag) {
+        mLogTag = logTag;
+    }
+
+    /**
+     * Subclasses must override this to allow error reporting code to compose
+     * the correct histogram name.
+     *
+     * Ensure that you define the new histograms if you define a new class!
+     */
+    protected abstract String getTelemetryPrefix();
+
+    /**
+     * Errors are recorded in telemetry using an enumerated histogram.
+     *
+     * <https://developer.mozilla.org/en-US/docs/Mozilla/Performance/
+     * Adding_a_new_Telemetry_probe#Choosing_a_Histogram_Type>
+     *
+     * These are the allowable enumeration values. Keep these in sync with the
+     * histogram definition!
+     *
+     */
+    private static enum TelemetryErrorOp {
+        BULKINSERT (0),
+        DELETE     (1),
+        INSERT     (2),
+        QUERY      (3),
+        UPDATE     (4);
+
+        private final int bucket;
+
+        TelemetryErrorOp(final int bucket) {
+            this.bucket = bucket;
+        }
+
+        public int getBucket() {
+            return bucket;
+        }
+    }
+
+    @Override
+    public void shutdown() {
+        if (mDatabasePerProfile == null) {
+            return;
+        }
+
+        synchronized (this) {
+            for (SQLiteBridge bridge : mDatabasePerProfile.values()) {
+                if (bridge != null) {
+                    try {
+                        bridge.close();
+                    } catch (Exception ex) { }
+                }
+            }
+            mDatabasePerProfile = null;
+        }
+        super.shutdown();
+    }
+
+    @Override
+    public void finalize() {
+        shutdown();
+    }
+
+    /**
+     * Return true of the query is from Firefox Sync.
+     * @param uri query URI
+     */
+    public static boolean isCallerSync(Uri uri) {
+        String isSync = uri.getQueryParameter(BrowserContract.PARAM_IS_SYNC);
+        return !TextUtils.isEmpty(isSync);
+    }
+
+    private SQLiteBridge getDB(Context context, final String databasePath) {
+        SQLiteBridge bridge = null;
+
+        boolean dbNeedsSetup = true;
+        try {
+            String resourcePath = context.getPackageResourcePath();
+            GeckoLoader.loadSQLiteLibs(context, resourcePath);
+            GeckoLoader.loadNSSLibs(context, resourcePath);
+            bridge = SQLiteBridge.openDatabase(databasePath, null, 0);
+            int version = bridge.getVersion();
+            dbNeedsSetup = version != getDBVersion();
+        } catch (SQLiteBridgeException ex) {
+            // close the database
+            if (bridge != null) {
+                bridge.close();
+            }
+
+            // this will throw if the database can't be found
+            // we should attempt to set it up if Gecko is running
+            dbNeedsSetup = true;
+            Log.e(mLogTag, "Error getting version ", ex);
+
+            // if Gecko is not running, we should bail out. Otherwise we try to
+            // let Gecko build the database for us
+            if (!GeckoThread.isRunning()) {
+                Log.e(mLogTag, "Can not set up database. Gecko is not running");
+                return null;
+            }
+        }
+
+        // If the database is not set up yet, or is the wrong schema version, we send an initialize
+        // call to Gecko. Gecko will handle building the database file correctly, as well as any
+        // migrations that are necessary
+        if (dbNeedsSetup) {
+            bridge = null;
+            initGecko();
+        }
+        return bridge;
+    }
+
+    /**
+     * Returns the absolute path of a database file depending on the specified profile and dbName.
+     * @param profile
+     *          the profile whose dbPath must be returned
+     * @param dbName
+     *          the name of the db file whose absolute path must be returned
+     * @return the absolute path of the db file or <code>null</code> if it was not possible to retrieve a valid path
+     *
+     */
+    private String getDatabasePathForProfile(String profile, String dbName) {
+        // Depends on the vagaries of GeckoProfile.get, so null check for safety.
+        File profileDir = GeckoProfile.get(mContext, profile).getDir();
+        if (profileDir == null) {
+            return null;
+        }
+
+        String databasePath = new File(profileDir, dbName).getAbsolutePath();
+        return databasePath;
+    }
+
+    /**
+     * Returns a SQLiteBridge object according to the specified profile id and to the name of db related to the
+     * current provider instance.
+     * @param profile
+     *          the id of the profile to be used to retrieve the related SQLiteBridge
+     * @return the <code>SQLiteBridge</code> related to the specified profile id or <code>null</code> if it was
+     *         not possible to retrieve a valid SQLiteBridge
+     */
+    private SQLiteBridge getDatabaseForProfile(String profile) {
+        if (profile == null) {
+            profile = GeckoProfile.get(mContext).getName();
+            Log.d(mLogTag, "No profile provided, using '" + profile + "'");
+        }
+
+        final String dbName = getDBName();
+        String mapKey = profile + "/" + dbName;
+
+        SQLiteBridge db = null;
+        synchronized (this) {
+            db = mDatabasePerProfile.get(mapKey);
+            if (db != null) {
+                return db;
+            }
+            final String dbPath = getDatabasePathForProfile(profile, dbName);
+            if (dbPath == null) {
+                Log.e(mLogTag, "Failed to get a valid db path for profile '" + profile + "'' dbName '" + dbName + "'");
+                return null;
+            }
+            db = getDB(mContext, dbPath);
+            if (db != null) {
+                mDatabasePerProfile.put(mapKey, db);
+            }
+        }
+        return db;
+    }
+
+    /**
+     * Returns a SQLiteBridge object according to the specified profile path and to the name of db related to the
+     * current provider instance.
+     * @param profilePath
+     *          the profilePath to be used to retrieve the related SQLiteBridge
+     * @return the <code>SQLiteBridge</code> related to the specified profile path or <code>null</code> if it was
+     *         not possible to retrieve a valid <code>SQLiteBridge</code>
+     */
+    private SQLiteBridge getDatabaseForProfilePath(String profilePath) {
+        File profileDir = new File(profilePath, getDBName());
+        final String dbPath = profileDir.getPath();
+        return getDatabaseForDBPath(dbPath);
+    }
+
+    /**
+     * Returns a SQLiteBridge object according to the specified file path.
+     * @param dbPath
+     *          the path of the file to be used to retrieve the related SQLiteBridge
+     * @return the <code>SQLiteBridge</code> related to the specified file path or <code>null</code> if it was
+     *         not possible to retrieve a valid <code>SQLiteBridge</code>
+     *
+     */
+    private SQLiteBridge getDatabaseForDBPath(String dbPath) {
+        SQLiteBridge db = null;
+        synchronized (this) {
+            db = mDatabasePerProfile.get(dbPath);
+            if (db != null) {
+                return db;
+            }
+            db = getDB(mContext, dbPath);
+            if (db != null) {
+                mDatabasePerProfile.put(dbPath, db);
+            }
+        }
+        return db;
+    }
+
+    /**
+     * Returns a SQLiteBridge object to be used to perform operations on the given <code>Uri</code>.
+     * @param uri
+     *          the <code>Uri</code> to be used to retrieve the related SQLiteBridge
+     * @return a <code>SQLiteBridge</code> object to be used on the given uri or <code>null</code> if it was
+     *         not possible to retrieve a valid <code>SQLiteBridge</code>
+     *
+     */
+    private SQLiteBridge getDatabase(Uri uri) {
+        String profile = null;
+        String profilePath = null;
+
+        profile = uri.getQueryParameter(BrowserContract.PARAM_PROFILE);
+        profilePath = uri.getQueryParameter(BrowserContract.PARAM_PROFILE_PATH);
+
+        // Testing will specify the absolute profile path
+        if (profilePath != null) {
+            return getDatabaseForProfilePath(profilePath);
+        }
+        return getDatabaseForProfile(profile);
+    }
+
+    @Override
+    public boolean onCreate() {
+        mContext = getContext();
+        synchronized (this) {
+            mDatabasePerProfile = new HashMap<String, SQLiteBridge>();
+        }
+        return true;
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        return null;
+    }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+        int deleted = 0;
+        final SQLiteBridge db = getDatabase(uri);
+        if (db == null) {
+            return deleted;
+        }
+
+        try {
+            deleted = db.delete(getTable(uri), selection, selectionArgs);
+        } catch (SQLiteBridgeException ex) {
+            reportError(ex, TelemetryErrorOp.DELETE);
+            throw ex;
+        }
+
+        return deleted;
+    }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        long id = -1;
+        final SQLiteBridge db = getDatabase(uri);
+
+        // If we can not get a SQLiteBridge instance, its likely that the database
+        // has not been set up and Gecko is not running. We return null and expect
+        // callers to try again later
+        if (db == null) {
+            return null;
+        }
+
+        setupDefaults(uri, values);
+
+        boolean useTransaction = !db.inTransaction();
+        try {
+            if (useTransaction) {
+                db.beginTransaction();
+            }
+
+            // onPreInsert does a check for the item in the deleted table in some cases
+            // so we put it inside this transaction
+            onPreInsert(values, uri, db);
+            id = db.insert(getTable(uri), null, values);
+
+            if (useTransaction) {
+                db.setTransactionSuccessful();
+            }
+        } catch (SQLiteBridgeException ex) {
+            reportError(ex, TelemetryErrorOp.INSERT);
+            throw ex;
+        } finally {
+            if (useTransaction) {
+                db.endTransaction();
+            }
+        }
+
+        return ContentUris.withAppendedId(uri, id);
+    }
+
+    @Override
+    public int bulkInsert(Uri uri, ContentValues[] allValues) {
+        final SQLiteBridge db = getDatabase(uri);
+        // If we can not get a SQLiteBridge instance, its likely that the database
+        // has not been set up and Gecko is not running. We return 0 and expect
+        // callers to try again later
+        if (db == null) {
+            return 0;
+        }
+
+        int rowsAdded = 0;
+
+        String table = getTable(uri);
+
+        try {
+            db.beginTransaction();
+            for (ContentValues initialValues : allValues) {
+                ContentValues values = new ContentValues(initialValues);
+                setupDefaults(uri, values);
+                onPreInsert(values, uri, db);
+                db.insert(table, null, values);
+                rowsAdded++;
+            }
+            db.setTransactionSuccessful();
+        } catch (SQLiteBridgeException ex) {
+            reportError(ex, TelemetryErrorOp.BULKINSERT);
+            throw ex;
+        } finally {
+            db.endTransaction();
+        }
+
+        if (rowsAdded > 0) {
+            final boolean shouldSyncToNetwork = !isCallerSync(uri);
+            mContext.getContentResolver().notifyChange(uri, null, shouldSyncToNetwork);
+        }
+
+        return rowsAdded;
+    }
+
+    @Override
+    public int update(Uri uri, ContentValues values, String selection,
+            String[] selectionArgs) {
+        int updated = 0;
+        final SQLiteBridge db = getDatabase(uri);
+
+        // If we can not get a SQLiteBridge instance, its likely that the database
+        // has not been set up and Gecko is not running. We return null and expect
+        // callers to try again later
+        if (db == null) {
+            return updated;
+        }
+
+        onPreUpdate(values, uri, db);
+
+        try {
+            updated = db.update(getTable(uri), values, selection, selectionArgs);
+        } catch (SQLiteBridgeException ex) {
+            reportError(ex, TelemetryErrorOp.UPDATE);
+            throw ex;
+        }
+
+        return updated;
+    }
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection,
+            String[] selectionArgs, String sortOrder) {
+        Cursor cursor = null;
+        final SQLiteBridge db = getDatabase(uri);
+
+        // If we can not get a SQLiteBridge instance, its likely that the database
+        // has not been set up and Gecko is not running. We return null and expect
+        // callers to try again later
+        if (db == null) {
+            return cursor;
+        }
+
+        sortOrder = getSortOrder(uri, sortOrder);
+
+        try {
+            cursor = db.query(getTable(uri), projection, selection, selectionArgs, null, null, sortOrder, null);
+            onPostQuery(cursor, uri, db);
+        } catch (SQLiteBridgeException ex) {
+            reportError(ex, TelemetryErrorOp.QUERY);
+            throw ex;
+        }
+
+        return cursor;
+    }
+
+    private String getHistogram(SQLiteBridgeException e) {
+        // If you add values here, make sure to update
+        // toolkit/components/telemetry/Histograms.json.
+        if (ERROR_MESSAGE_DATABASE_IS_LOCKED.equals(e.getMessage())) {
+            return getTelemetryPrefix() + "_LOCKED";
+        }
+        return null;
+    }
+
+    protected void reportError(SQLiteBridgeException e, TelemetryErrorOp op) {
+        Log.e(mLogTag, "Error in database " + op.name(), e);
+        final String histogram = getHistogram(e);
+        if (histogram == null) {
+            return;
+        }
+
+        Telemetry.addToHistogram(histogram, op.getBucket());
+    }
+
+    protected abstract String getDBName();
+
+    protected abstract int getDBVersion();
+
+    protected abstract String getTable(Uri uri);
+
+    protected abstract String getSortOrder(Uri uri, String aRequested);
+
+    protected abstract void setupDefaults(Uri uri, ContentValues values);
+
+    protected abstract void initGecko();
+
+    protected abstract void onPreInsert(ContentValues values, Uri uri, SQLiteBridge db);
+
+    protected abstract void onPreUpdate(ContentValues values, Uri uri, SQLiteBridge db);
+
+    protected abstract void onPostQuery(Cursor cursor, Uri uri, SQLiteBridge db);
+}

mobile/android/base/java/org/mozilla/gecko/db/SearchHistoryProvider.java

@@ -0,0 +1,127 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.db.BrowserContract;
+import org.mozilla.gecko.db.BrowserContract.SearchHistory;
+
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+public class SearchHistoryProvider extends SharedBrowserDatabaseProvider {
+    private static final String LOG_TAG = "GeckoSearchProvider";
+    private static final boolean DEBUG_ENABLED = false;
+
+    /**
+     * Collapse whitespace.
+     */
+    private String stripWhitespace(String query) {
+        if (TextUtils.isEmpty(query)) {
+            return "";
+        }
+
+        // Collapse whitespace
+        return query.trim().replaceAll("\\s+", " ");
+    }
+
+
+    @Override
+    public Uri insertInTransaction(Uri uri, ContentValues cv) {
+        final String query = stripWhitespace(cv.getAsString(SearchHistory.QUERY));
+
+        // We don't support inserting empty search queries.
+        if (TextUtils.isEmpty(query)) {
+            return null;
+        }
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        long id = -1;
+
+        /*
+         * Attempt to insert the query. The catch block handles the case when
+         * the query already exists in the DB.
+         */
+        try {
+            cv.put(SearchHistory.QUERY, query);
+            cv.put(SearchHistory.VISITS, 1);
+            cv.put(SearchHistory.DATE_LAST_VISITED, System.currentTimeMillis());
+
+            id = db.insertOrThrow(SearchHistory.TABLE_NAME, null, cv);
+
+            if (id > 0) {
+                return ContentUris.withAppendedId(uri, id);
+            }
+        } catch (SQLException e) {
+            // This happens when the column already exists for this term.
+            if (DEBUG_ENABLED) {
+                Log.w(LOG_TAG, String.format("Query `%s` already in db", query));
+            }
+        }
+
+        /*
+         * Increment the VISITS counter and update the DATE_LAST_VISITED.
+         */
+        final String sql = "UPDATE " + SearchHistory.TABLE_NAME + " SET " +
+                            SearchHistory.VISITS + " = " + SearchHistory.VISITS + " + 1, " +
+                            SearchHistory.DATE_LAST_VISITED + " = " + System.currentTimeMillis() +
+                            " WHERE " + SearchHistory.QUERY + " = ?";
+
+        final Cursor c = db.rawQuery(sql, new String[] { query });
+
+        try {
+            if (c.getCount() > 1) {
+                // There is a UNIQUE constraint on the QUERY column,
+                // so there should only be one match.
+                return null;
+            }
+            if (c.moveToFirst()) {
+                return ContentUris.withAppendedId(uri, c.getInt(c.getColumnIndex(SearchHistory._ID)));
+            }
+        } finally {
+            c.close();
+        }
+
+        return null;
+    }
+
+    @Override
+    public int deleteInTransaction(Uri uri, String selection, String[] selectionArgs) {
+        return getWritableDatabase(uri).delete(SearchHistory.TABLE_NAME,
+                                               selection, selectionArgs);
+    }
+
+    /**
+     * Since we are managing counts and the full-text db, an update
+     * could mangle the internal state. So we disable it.
+     */
+    @Override
+    public int updateInTransaction(Uri uri, ContentValues values, String selection,
+            String[] selectionArgs) {
+        throw new UnsupportedOperationException("This content provider does not support updating items");
+    }
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection,
+            String[] selectionArgs, String sortOrder) {
+        final String groupBy = null;
+        final String having = null;
+        final String limit = uri.getQueryParameter(BrowserContract.PARAM_LIMIT);
+        final Cursor cursor = getReadableDatabase(uri).query(SearchHistory.TABLE_NAME, projection,
+                selection, selectionArgs, groupBy, having, sortOrder, limit);
+        cursor.setNotificationUri(getContext().getContentResolver(), uri);
+        return cursor;
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        return SearchHistory.CONTENT_TYPE;
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/Searches.java

@@ -0,0 +1,12 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentResolver;
+
+public interface Searches {
+    public void insert(ContentResolver cr, String query);
+}

mobile/android/base/java/org/mozilla/gecko/db/SharedBrowserDatabaseProvider.java

@@ -0,0 +1,128 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.AppConstants.Versions;
+import org.mozilla.gecko.db.BrowserContract.CommonColumns;
+import org.mozilla.gecko.db.BrowserContract.SyncColumns;
+import org.mozilla.gecko.db.PerProfileDatabases.DatabaseHelperFactory;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.util.Log;
+
+/**
+ * A ContentProvider subclass that provides per-profile browser.db access
+ * that can be safely shared between multiple providers.
+ *
+ * If multiple ContentProvider classes wish to share a database, it's
+ * vitally important that they use the same SQLiteOpenHelpers for access.
+ *
+ * Failure to do so can cause accidental concurrent writes, with the result
+ * being unexpected SQLITE_BUSY errors.
+ *
+ * This class provides a static {@link PerProfileDatabases} instance, lazily
+ * initialized within {@link SharedBrowserDatabaseProvider#onCreate()}.
+ */
+public abstract class SharedBrowserDatabaseProvider extends AbstractPerProfileDatabaseProvider {
+    private static final String LOGTAG = SharedBrowserDatabaseProvider.class.getSimpleName();
+
+    private static PerProfileDatabases<BrowserDatabaseHelper> databases;
+
+    @Override
+    protected PerProfileDatabases<BrowserDatabaseHelper> getDatabases() {
+        return databases;
+    }
+
+    @Override
+    public void shutdown() {
+        synchronized (SharedBrowserDatabaseProvider.class) {
+            databases.shutdown();
+            databases = null;
+        }
+    }
+
+    @Override
+    public boolean onCreate() {
+        // If necessary, do the shared DB work.
+        synchronized (SharedBrowserDatabaseProvider.class) {
+            if (databases != null) {
+                return true;
+            }
+
+            final DatabaseHelperFactory<BrowserDatabaseHelper> helperFactory = new DatabaseHelperFactory<BrowserDatabaseHelper>() {
+                @Override
+                public BrowserDatabaseHelper makeDatabaseHelper(Context context, String databasePath) {
+                    final BrowserDatabaseHelper helper = new BrowserDatabaseHelper(context, databasePath);
+                    if (Versions.feature16Plus) {
+                        helper.setWriteAheadLoggingEnabled(true);
+                    }
+                    return helper;
+                }
+            };
+
+            databases = new PerProfileDatabases<BrowserDatabaseHelper>(getContext(), BrowserDatabaseHelper.DATABASE_NAME, helperFactory);
+        }
+
+        return true;
+    }
+
+    /**
+     * Clean up some deleted records from the specified table.
+     *
+     * If called in an existing transaction, it is the caller's responsibility
+     * to ensure that the transaction is already upgraded to a writer, because
+     * this method issues a read followed by a write, and thus is potentially
+     * vulnerable to an unhandled SQLITE_BUSY failure during the upgrade.
+     *
+     * If not called in an existing transaction, no new explicit transaction
+     * will be begun.
+     */
+    protected void cleanUpSomeDeletedRecords(Uri fromUri, String tableName) {
+        Log.d(LOGTAG, "Cleaning up deleted records from " + tableName);
+
+        // We clean up records marked as deleted that are older than a
+        // predefined max age. It's important not be too greedy here and
+        // remove only a few old deleted records at a time.
+
+        // we cleanup records marked as deleted that are older than a
+        // predefined max age. It's important not be too greedy here and
+        // remove only a few old deleted records at a time.
+
+        // Maximum age of deleted records to be cleaned up (20 days in ms)
+        final long MAX_AGE_OF_DELETED_RECORDS = 86400000 * 20;
+
+        // Number of records marked as deleted to be removed
+        final long DELETED_RECORDS_PURGE_LIMIT = 5;
+
+        // Android SQLite doesn't have LIMIT on DELETE. Instead, query for the
+        // IDs of matching rows, then delete them in one go.
+        final long now = System.currentTimeMillis();
+        final String selection = getDeletedItemSelection(now - MAX_AGE_OF_DELETED_RECORDS);
+
+        final String profile = fromUri.getQueryParameter(BrowserContract.PARAM_PROFILE);
+        final SQLiteDatabase db = getWritableDatabaseForProfile(profile, isTest(fromUri));
+        final String limit = Long.toString(DELETED_RECORDS_PURGE_LIMIT, 10);
+        final Cursor cursor = db.query(tableName, new String[] { CommonColumns._ID }, selection, null, null, null, null, limit);
+        final String inClause;
+        try {
+            inClause = DBUtils.computeSQLInClauseFromLongs(cursor, CommonColumns._ID);
+        } finally {
+            cursor.close();
+        }
+
+        db.delete(tableName, inClause, null);
+    }
+
+    // Override this, or override cleanUpSomeDeletedRecords.
+    protected String getDeletedItemSelection(long earlierThan) {
+        if (earlierThan == -1L) {
+            return SyncColumns.IS_DELETED + " = 1";
+        }
+        return SyncColumns.IS_DELETED + " = 1 AND " + SyncColumns.DATE_MODIFIED + " <= " + earlierThan;
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/SuggestedSites.java

@@ -0,0 +1,629 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.Context;
+import android.content.ContentResolver;
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.Editor;
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.database.MatrixCursor.RowBuilder;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.Set;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.mozilla.gecko.annotation.RobocopTarget;
+import org.mozilla.gecko.GeckoSharedPrefs;
+import org.mozilla.gecko.GeckoProfile;
+import org.mozilla.gecko.Locales;
+import org.mozilla.gecko.R;
+import org.mozilla.gecko.distribution.Distribution;
+import org.mozilla.gecko.restrictions.Restrictions;
+import org.mozilla.gecko.util.RawResource;
+import org.mozilla.gecko.util.ThreadUtils;
+import org.mozilla.gecko.preferences.GeckoPreferences;
+
+/**
+ * {@code SuggestedSites} provides API to get a list of locale-specific
+ * suggested sites to be used in Fennec's top sites panel. It provides
+ * only a single method to fetch the list as a {@code Cursor}. This cursor
+ * will then be wrapped by {@code TopSitesCursorWrapper} to blend top,
+ * pinned, and suggested sites in the UI. The returned {@code Cursor}
+ * uses its own schema defined in {@code BrowserContract.SuggestedSites}
+ * for clarity.
+ *
+ * Under the hood, {@code SuggestedSites} keeps reference to the
+ * parsed list of sites to avoid reparsing the JSON file on every
+ * {@code get()} call.
+ *
+ * The default list of suggested sites is stored in a raw Android
+ * resource ({@code R.raw.suggestedsites}) which is dynamically
+ * generated at build time for each target locale.
+ *
+ * Changes to the list of suggested sites are saved in SharedPreferences.
+ */
+@RobocopTarget
+public class SuggestedSites {
+    private static final String LOGTAG = "GeckoSuggestedSites";
+
+    // SharedPreference key for suggested sites that should be hidden.
+    public static final String PREF_SUGGESTED_SITES_HIDDEN = GeckoPreferences.NON_PREF_PREFIX + "suggestedSites.hidden";
+    public static final String PREF_SUGGESTED_SITES_HIDDEN_OLD = "suggestedSites.hidden";
+
+    // Locale used to generate the current suggested sites.
+    public static final String PREF_SUGGESTED_SITES_LOCALE = GeckoPreferences.NON_PREF_PREFIX + "suggestedSites.locale";
+    public static final String PREF_SUGGESTED_SITES_LOCALE_OLD = "suggestedSites.locale";
+
+    // File in profile dir with the list of suggested sites.
+    private static final String FILENAME = "suggestedsites.json";
+
+    private static final String[] COLUMNS = new String[] {
+        BrowserContract.SuggestedSites._ID,
+        BrowserContract.SuggestedSites.URL,
+        BrowserContract.SuggestedSites.TITLE,
+        BrowserContract.Combined.HISTORY_ID
+    };
+
+    private static final String JSON_KEY_URL = "url";
+    private static final String JSON_KEY_TITLE = "title";
+    private static final String JSON_KEY_IMAGE_URL = "imageurl";
+    private static final String JSON_KEY_BG_COLOR = "bgcolor";
+    private static final String JSON_KEY_RESTRICTED = "restricted";
+
+    private static class Site {
+        public final String url;
+        public final String title;
+        public final String imageUrl;
+        public final String bgColor;
+        public final boolean restricted;
+
+        public Site(JSONObject json) throws JSONException {
+            this.restricted =  !json.isNull(JSON_KEY_RESTRICTED);
+            this.url = json.getString(JSON_KEY_URL);
+            this.title = json.getString(JSON_KEY_TITLE);
+            this.imageUrl = json.getString(JSON_KEY_IMAGE_URL);
+            this.bgColor = json.getString(JSON_KEY_BG_COLOR);
+
+            validate();
+        }
+
+        public Site(String url, String title, String imageUrl, String bgColor) {
+            this.url = url;
+            this.title = title;
+            this.imageUrl = imageUrl;
+            this.bgColor = bgColor;
+            this.restricted = false;
+
+            validate();
+        }
+
+        private void validate() {
+            // Site instances must have non-empty values for all properties except IDs.
+            if (TextUtils.isEmpty(url) ||
+                TextUtils.isEmpty(title) ||
+                TextUtils.isEmpty(imageUrl) ||
+                TextUtils.isEmpty(bgColor)) {
+                throw new IllegalStateException("Suggested sites must have a URL, title, " +
+                                                "image URL, and background color.");
+            }
+        }
+
+        @Override
+        public String toString() {
+            return "{ url = " + url + "\n" +
+                     "restricted = " + restricted + "\n" +
+                     "title = " + title + "\n" +
+                     "imageUrl = " + imageUrl + "\n" +
+                     "bgColor = " + bgColor + " }";
+        }
+
+        public JSONObject toJSON() throws JSONException {
+            final JSONObject json = new JSONObject();
+
+            if (restricted) {
+                json.put(JSON_KEY_RESTRICTED, true);
+            }
+
+            json.put(JSON_KEY_URL, url);
+            json.put(JSON_KEY_TITLE, title);
+            json.put(JSON_KEY_IMAGE_URL, imageUrl);
+            json.put(JSON_KEY_BG_COLOR, bgColor);
+
+            return json;
+        }
+    }
+
+    final Context context;
+    final Distribution distribution;
+    private File cachedFile;
+    private Map<String, Site> cachedSites;
+    private Set<String> cachedBlacklist;
+
+    public SuggestedSites(Context appContext) {
+        this(appContext, null);
+    }
+
+    public SuggestedSites(Context appContext, Distribution distribution) {
+        this(appContext, distribution, null);
+    }
+
+    public SuggestedSites(Context appContext, Distribution distribution, File file) {
+        this.context = appContext;
+        this.distribution = distribution;
+        this.cachedFile = file;
+    }
+
+    synchronized File getFile() {
+        if (cachedFile == null) {
+            cachedFile = GeckoProfile.get(context).getFile(FILENAME);
+        }
+        return cachedFile;
+    }
+
+    private static boolean isNewLocale(Context context, Locale requestedLocale) {
+        final SharedPreferences prefs = GeckoSharedPrefs.forProfile(context);
+
+        String locale = prefs.getString(PREF_SUGGESTED_SITES_LOCALE_OLD, null);
+        if (locale != null) {
+          // Migrate the old pref and remove it
+          final Editor editor = prefs.edit();
+          editor.remove(PREF_SUGGESTED_SITES_LOCALE_OLD);
+          editor.putString(PREF_SUGGESTED_SITES_LOCALE, locale);
+          editor.apply();
+        } else {
+          locale = prefs.getString(PREF_SUGGESTED_SITES_LOCALE, null);
+        }
+        if (locale == null) {
+            // Initialize config with the current locale
+            updateSuggestedSitesLocale(context);
+            return true;
+        }
+
+        return !TextUtils.equals(requestedLocale.toString(), locale);
+    }
+
+    /**
+     * Return the current locale and its fallback (en_US) in order.
+     */
+    private static List<Locale> getAcceptableLocales() {
+        final List<Locale> locales = new ArrayList<Locale>();
+
+        final Locale defaultLocale = Locale.getDefault();
+        locales.add(defaultLocale);
+
+        if (!defaultLocale.equals(Locale.US)) {
+            locales.add(Locale.US);
+        }
+
+        return locales;
+    }
+
+    private static Map<String, Site> loadSites(File f) throws IOException {
+        Scanner scanner = null;
+
+        try {
+            scanner = new Scanner(f, "UTF-8");
+            return loadSites(scanner.useDelimiter("\\A").next());
+        } finally {
+            if (scanner != null) {
+                scanner.close();
+            }
+        }
+    }
+
+    private static Map<String, Site> loadSites(String jsonString) {
+        if (TextUtils.isEmpty(jsonString)) {
+            return null;
+        }
+
+        Map<String, Site> sites = null;
+
+        try {
+            final JSONArray jsonSites = new JSONArray(jsonString);
+            sites = new LinkedHashMap<String, Site>(jsonSites.length());
+
+            final int count = jsonSites.length();
+            for (int i = 0; i < count; i++) {
+                final Site site = new Site(jsonSites.getJSONObject(i));
+                sites.put(site.url, site);
+            }
+        } catch (Exception e) {
+            Log.e(LOGTAG, "Failed to refresh suggested sites", e);
+            return null;
+        }
+
+        return sites;
+    }
+
+    /**
+     * Saves suggested sites file to disk. Access to this method should
+     * be synchronized on 'file'.
+     */
+    static void saveSites(File f, Map<String, Site> sites) {
+        ThreadUtils.assertNotOnUiThread();
+
+        if (sites == null || sites.isEmpty()) {
+            return;
+        }
+
+        OutputStreamWriter osw = null;
+
+        try {
+            final JSONArray jsonSites = new JSONArray();
+            for (Site site : sites.values()) {
+                jsonSites.put(site.toJSON());
+            }
+
+            osw = new OutputStreamWriter(new FileOutputStream(f), "UTF-8");
+
+            final String jsonString = jsonSites.toString();
+            osw.write(jsonString, 0, jsonString.length());
+        } catch (Exception e) {
+            Log.e(LOGTAG, "Failed to save suggested sites", e);
+        } finally {
+            if (osw != null) {
+                try {
+                    osw.close();
+                } catch (IOException e) {
+                    // Ignore.
+                }
+            }
+        }
+    }
+
+    private void maybeWaitForDistribution() {
+        if (distribution == null) {
+            return;
+        }
+
+        distribution.addOnDistributionReadyCallback(new Distribution.ReadyCallback() {
+            @Override
+            public void distributionNotFound() {
+                // If distribution doesn't exist, simply continue to load
+                // suggested sites directly from resources. See refresh().
+            }
+
+            @Override
+            public void distributionFound(Distribution distribution) {
+                Log.d(LOGTAG, "Running post-distribution task: suggested sites.");
+                // Merge suggested sites from distribution with the
+                // default ones. Distribution takes precedence.
+                Map<String, Site> sites = loadFromDistribution(distribution);
+                if (sites == null) {
+                    sites = new LinkedHashMap<String, Site>();
+                }
+                sites.putAll(loadFromResource());
+
+                // Update cached list of sites.
+                setCachedSites(sites);
+
+                // Save the result to disk.
+                final File file = getFile();
+                synchronized (file) {
+                    saveSites(file, sites);
+                }
+
+                // Then notify any active loaders about the changes.
+                final ContentResolver cr = context.getContentResolver();
+                cr.notifyChange(BrowserContract.SuggestedSites.CONTENT_URI, null);
+            }
+
+            @Override
+            public void distributionArrivedLate(Distribution distribution) {
+                distributionFound(distribution);
+            }
+        });
+    }
+
+    /**
+     * Loads suggested sites from a distribution file either matching the
+     * current locale or with the fallback locale (en-US).
+     *
+     * It's assumed that the given distribution instance is ready to be
+     * used and exists.
+     */
+    static Map<String, Site> loadFromDistribution(Distribution dist) {
+        for (Locale locale : getAcceptableLocales()) {
+            try {
+                final String languageTag = Locales.getLanguageTag(locale);
+                final String path = String.format("suggestedsites/locales/%s/%s",
+                                                  languageTag, FILENAME);
+
+                final File f = dist.getDistributionFile(path);
+                if (f == null) {
+                    Log.d(LOGTAG, "No suggested sites for locale: " + languageTag);
+                    continue;
+                }
+
+                return loadSites(f);
+            } catch (Exception e) {
+                Log.e(LOGTAG, "Failed to open suggested sites for locale " +
+                              locale + " in distribution.", e);
+            }
+        }
+
+        return null;
+    }
+
+    private Map<String, Site> loadFromProfile() {
+        try {
+            final File file = getFile();
+            synchronized (file) {
+                return loadSites(file);
+            }
+        } catch (FileNotFoundException e) {
+            maybeWaitForDistribution();
+        } catch (IOException e) {
+            // Fall through, return null.
+        }
+
+        return null;
+    }
+
+    Map<String, Site> loadFromResource() {
+        try {
+            return loadSites(RawResource.getAsString(context, R.raw.suggestedsites));
+        } catch (IOException e) {
+            return null;
+        }
+    }
+
+    private synchronized void setCachedSites(Map<String, Site> sites) {
+        cachedSites = Collections.unmodifiableMap(sites);
+        updateSuggestedSitesLocale(context);
+    }
+
+    /**
+     * Refreshes the cached list of sites either from the default raw
+     * source or standard file location. This will be called on every
+     * cache miss during a {@code get()} call.
+     */
+    private void refresh() {
+        Log.d(LOGTAG, "Refreshing suggested sites from file");
+
+        Map<String, Site> sites = loadFromProfile();
+        if (sites == null) {
+            sites = loadFromResource();
+        }
+
+        // Update cached list of sites.
+        if (sites != null) {
+            setCachedSites(sites);
+        }
+    }
+
+    private static void updateSuggestedSitesLocale(Context context) {
+        final Editor editor = GeckoSharedPrefs.forProfile(context).edit();
+        editor.putString(PREF_SUGGESTED_SITES_LOCALE, Locale.getDefault().toString());
+        editor.apply();
+    }
+
+    private synchronized Site getSiteForUrl(String url) {
+        if (cachedSites == null) {
+            return null;
+        }
+
+        return cachedSites.get(url);
+    }
+
+    /**
+     * Returns a {@code Cursor} with the list of suggested websites.
+     *
+     * @param limit maximum number of suggested sites.
+     */
+    public Cursor get(int limit) {
+        return get(limit, Locale.getDefault());
+    }
+
+    /**
+     * Returns a {@code Cursor} with the list of suggested websites.
+     *
+     * @param limit maximum number of suggested sites.
+     * @param locale the target locale.
+     */
+    public Cursor get(int limit, Locale locale) {
+        return get(limit, locale, null);
+    }
+
+    /**
+     * Returns a {@code Cursor} with the list of suggested websites.
+     *
+     * @param limit maximum number of suggested sites.
+     * @param excludeUrls list of URLs to be excluded from the list.
+     */
+    public Cursor get(int limit, List<String> excludeUrls) {
+        return get(limit, Locale.getDefault(), excludeUrls);
+    }
+
+    /**
+     * Returns a {@code Cursor} with the list of suggested websites.
+     *
+     * @param limit maximum number of suggested sites.
+     * @param locale the target locale.
+     * @param excludeUrls list of URLs to be excluded from the list.
+     */
+    public synchronized Cursor get(int limit, Locale locale, List<String> excludeUrls) {
+        final MatrixCursor cursor = new MatrixCursor(COLUMNS);
+        final boolean isNewLocale = isNewLocale(context, locale);
+
+        // Force the suggested sites file in profile dir to be re-generated
+        // if the locale has changed.
+        if (isNewLocale) {
+            getFile().delete();
+        }
+
+        if (cachedSites == null || isNewLocale) {
+            Log.d(LOGTAG, "No cached sites, refreshing.");
+            refresh();
+        }
+
+        // Return empty cursor if there was an error when
+        // loading the suggested sites or the list is empty.
+        if (cachedSites == null || cachedSites.isEmpty()) {
+            return cursor;
+        }
+
+        excludeUrls = includeBlacklist(excludeUrls);
+
+        final int sitesCount = cachedSites.size();
+        Log.d(LOGTAG, "Number of suggested sites: " + sitesCount);
+
+        final int maxCount = Math.min(limit, sitesCount);
+        // History IDS: real history is positive, -1 is no history id in the combined table
+        // hence we can start at -2 for suggested sites
+        int id = -1;
+        for (Site site : cachedSites.values()) {
+            // Decrement ID here: this ensure we have a consistent ID to URL mapping, even if items
+            // are removed. If we instead decremented at the point of insertion we'd end up with
+            // ID conflicts when a suggested site is removed. (note that cachedSites does not change
+            // while we're already showing topsites)
+            --id;
+            if (cursor.getCount() == maxCount) {
+                break;
+            }
+
+            if (excludeUrls != null && excludeUrls.contains(site.url)) {
+                continue;
+            }
+
+            final boolean restrictedProfile =  Restrictions.isRestrictedProfile(context);
+
+            if (restrictedProfile == site.restricted) {
+                final RowBuilder row = cursor.newRow();
+                row.add(id);
+                row.add(site.url);
+                row.add(site.title);
+                row.add(id);
+            }
+        }
+
+        cursor.setNotificationUri(context.getContentResolver(),
+                                  BrowserContract.SuggestedSites.CONTENT_URI);
+
+        return cursor;
+    }
+
+    public boolean contains(String url) {
+        return (getSiteForUrl(url) != null);
+    }
+
+    public String getImageUrlForUrl(String url) {
+        final Site site = getSiteForUrl(url);
+        return (site != null ? site.imageUrl : null);
+    }
+
+    public String getBackgroundColorForUrl(String url) {
+        final Site site = getSiteForUrl(url);
+        return (site != null ? site.bgColor : null);
+    }
+
+    private Set<String> loadBlacklist() {
+        Log.d(LOGTAG, "Loading blacklisted suggested sites from SharedPreferences.");
+        final Set<String> blacklist = new HashSet<String>();
+
+        final SharedPreferences prefs = GeckoSharedPrefs.forProfile(context);
+        String sitesString = prefs.getString(PREF_SUGGESTED_SITES_HIDDEN_OLD, null);
+        if (sitesString != null) {
+          // Migrate the old pref and remove it
+          final Editor editor = prefs.edit();
+          editor.remove(PREF_SUGGESTED_SITES_HIDDEN_OLD);
+          editor.putString(PREF_SUGGESTED_SITES_HIDDEN, sitesString);
+          editor.apply();
+        } else {
+          sitesString = prefs.getString(PREF_SUGGESTED_SITES_HIDDEN, null);
+        }
+
+        if (sitesString != null) {
+            for (String site : sitesString.trim().split(" ")) {
+                blacklist.add(Uri.decode(site));
+            }
+        }
+
+        return blacklist;
+    }
+
+    private List<String> includeBlacklist(List<String> originalList) {
+        if (cachedBlacklist == null) {
+            cachedBlacklist = loadBlacklist();
+        }
+
+        if (cachedBlacklist.isEmpty()) {
+            return originalList;
+        }
+
+        if (originalList == null) {
+            originalList = new ArrayList<String>();
+        }
+
+        originalList.addAll(cachedBlacklist);
+        return originalList;
+    }
+
+    /**
+     * Blacklist a suggested site so it will no longer be returned as a suggested site.
+     * This method should only be called from a background thread because it may write
+     * to SharedPreferences.
+     *
+     * Urls that are not Suggested Sites are ignored.
+     *
+     * @param url String url of site to blacklist
+     * @return true is blacklisted, false otherwise
+     */
+    public synchronized boolean hideSite(String url) {
+        ThreadUtils.assertNotOnUiThread();
+
+        if (cachedSites == null) {
+            refresh();
+            if (cachedSites == null) {
+                Log.w(LOGTAG, "Could not load suggested sites!");
+                return false;
+            }
+        }
+
+        if (cachedSites.containsKey(url)) {
+            if (cachedBlacklist == null) {
+                cachedBlacklist = loadBlacklist();
+            }
+
+            // Check if site has already been blacklisted, just in case.
+            if (!cachedBlacklist.contains(url)) {
+
+                saveToBlacklist(url);
+                cachedBlacklist.add(url);
+
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private void saveToBlacklist(String url) {
+        final SharedPreferences prefs = GeckoSharedPrefs.forProfile(context);
+        final String prefString = prefs.getString(PREF_SUGGESTED_SITES_HIDDEN, "");
+        final String siteString = prefString.concat(" " + Uri.encode(url));
+        prefs.edit().putString(PREF_SUGGESTED_SITES_HIDDEN, siteString).apply();
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/Table.java

@@ -0,0 +1,47 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+
+// Tables provide a basic wrapper around ContentProvider methods to make it simpler to add new tables into storage.
+// If you create a new Table type, make sure to add it to the sTables list in BrowserProvider to ensure it is queried.
+interface Table {
+    // Provides information to BrowserProvider about the type of URIs this Table can handle.
+    public static class ContentProviderInfo {
+        public final int id; // A number of ID for this table. Used by the UriMatcher in BrowserProvider
+        public final String name; // A name for this table. Will be appended onto uris querying this table
+                                  // This is also used to define the mimetype of data returned from this db, i.e.
+                                  // BrowserProvider will return "vnd.android.cursor.item/" + name
+
+        public ContentProviderInfo(int id, String name) {
+            if (name == null) {
+                throw new IllegalArgumentException("Content provider info must specify a name");
+            }
+            this.id = id;
+            this.name = name;
+        }
+    }
+
+    // Return a list of Info about the ContentProvider URIs this will match
+    ContentProviderInfo[] getContentProviderInfo();
+
+    // Called by BrowserDBHelper whenever the database is created or upgraded.
+    // Order in which tables are created/upgraded isn't guaranteed (yet), so be careful if your Table depends on something in a
+    // separate table.
+    void onCreate(SQLiteDatabase db);
+    void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion);
+
+    // Called by BrowserProvider when this database queried/modified
+    // The dbId here should match the dbId's you returned in your getContentProviderInfo() call
+    Cursor query(SQLiteDatabase db, Uri uri, int dbId, String[] projection, String selection, String[] selectionArgs, String sortOrder, String groupBy, String limit);
+    int update(SQLiteDatabase db, Uri uri, int dbId, ContentValues values, String selection, String[] selectionArgs);
+    long insert(SQLiteDatabase db, Uri uri, int dbId, ContentValues values);
+    int delete(SQLiteDatabase db, Uri uri, int dbId, String selection, String[] selectionArgs);
+};

mobile/android/base/java/org/mozilla/gecko/db/TabsAccessor.java

@@ -0,0 +1,28 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.database.Cursor;
+
+import org.mozilla.gecko.Tab;
+
+import java.util.List;
+
+public interface TabsAccessor {
+    public interface OnQueryTabsCompleteListener {
+        public void onQueryTabsComplete(List<RemoteClient> clients);
+    }
+
+    public Cursor getRemoteClientsByRecencyCursor(Context context);
+    public Cursor getRemoteTabsCursor(Context context);
+    public Cursor getRemoteTabsCursor(Context context, int limit);
+    public List<RemoteClient> getClientsWithoutTabsByRecencyFromCursor(final Cursor cursor);
+    public List<RemoteClient> getClientsFromCursor(final Cursor cursor);
+    public void getTabs(final Context context, final OnQueryTabsCompleteListener listener);
+    public void getTabs(final Context context, final int limit, final OnQueryTabsCompleteListener listener);
+    public void persistLocalTabs(final ContentResolver cr, final Iterable<Tab> tabs);
+}

mobile/android/base/java/org/mozilla/gecko/db/TabsProvider.java

@@ -0,0 +1,361 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.mozilla.gecko.db.BrowserContract.Clients;
+import org.mozilla.gecko.db.BrowserContract.Tabs;
+
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteQueryBuilder;
+import android.net.Uri;
+import android.text.TextUtils;
+
+public class TabsProvider extends SharedBrowserDatabaseProvider {
+    private static final long ONE_DAY_IN_MILLISECONDS = 1000 * 60 * 60 * 24;
+    private static final long ONE_WEEK_IN_MILLISECONDS = 7 * ONE_DAY_IN_MILLISECONDS;
+    private static final long THREE_WEEKS_IN_MILLISECONDS = 3 * ONE_WEEK_IN_MILLISECONDS;
+
+    static final String TABLE_TABS = "tabs";
+    static final String TABLE_CLIENTS = "clients";
+
+    static final int TABS = 600;
+    static final int TABS_ID = 601;
+    static final int CLIENTS = 602;
+    static final int CLIENTS_ID = 603;
+    static final int CLIENTS_RECENCY = 604;
+
+    // Exclude clients that are more than three weeks old and also any duplicates that are older than one week old.
+    static final String EXCLUDE_STALE_CLIENTS_SUBQUERY =
+    "(SELECT " + Clients.GUID +
+    ", " + Clients.NAME +
+    ", " + Clients.LAST_MODIFIED +
+    ", " + Clients.DEVICE_TYPE +
+    "  FROM " + TABLE_CLIENTS +
+    "  WHERE " + Clients.LAST_MODIFIED + " > %1$s " +
+    " GROUP BY " + Clients.NAME +
+    " UNION ALL " +
+    " SELECT c." +  Clients.GUID + " AS " + Clients.GUID +
+    ", c." + Clients.NAME + " AS " + Clients.NAME +
+    ", c." + Clients.LAST_MODIFIED + " AS " + Clients.LAST_MODIFIED +
+    ", c." + Clients.DEVICE_TYPE + " AS " + Clients.DEVICE_TYPE +
+    " FROM " + TABLE_CLIENTS + " AS c " +
+    " JOIN (" +
+        " SELECT " + Clients.GUID +
+        ", " + "MAX( " + Clients.LAST_MODIFIED + ") AS " + Clients.LAST_MODIFIED +
+        " FROM " + TABLE_CLIENTS +
+        " WHERE (" + Clients.LAST_MODIFIED + " < %1$s" + " AND " + Clients.LAST_MODIFIED + " > %2$s) AND " +
+        Clients.NAME + " NOT IN " + "( SELECT " + Clients.NAME + " FROM " + TABLE_CLIENTS + " WHERE " + Clients.LAST_MODIFIED + " > %1$s)" +
+        " GROUP BY " + Clients.NAME +
+    ") AS c2" +
+    " ON c." + Clients.GUID + " = c2." + Clients.GUID + ")";
+
+    static final String DEFAULT_TABS_SORT_ORDER = Clients.LAST_MODIFIED + " DESC, " + Tabs.LAST_USED + " DESC";
+    static final String DEFAULT_CLIENTS_SORT_ORDER = Clients.LAST_MODIFIED + " DESC";
+    static final String DEFAULT_CLIENTS_RECENCY_SORT_ORDER = "COALESCE(MAX(" + Tabs.LAST_USED + "), " + Clients.LAST_MODIFIED + ") DESC";
+
+    static final String INDEX_TABS_GUID = "tabs_guid_index";
+    static final String INDEX_TABS_POSITION = "tabs_position_index";
+
+    static final UriMatcher URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
+
+    static final Map<String, String> TABS_PROJECTION_MAP;
+    static final Map<String, String> CLIENTS_PROJECTION_MAP;
+    static final Map<String, String> CLIENTS_RECENCY_PROJECTION_MAP;
+
+    static {
+        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "tabs", TABS);
+        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "tabs/#", TABS_ID);
+        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "clients", CLIENTS);
+        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "clients/#", CLIENTS_ID);
+        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "clients_recency", CLIENTS_RECENCY);
+
+        HashMap<String, String> map;
+
+        map = new HashMap<String, String>();
+        map.put(Tabs._ID, Tabs._ID);
+        map.put(Tabs.TITLE, Tabs.TITLE);
+        map.put(Tabs.URL, Tabs.URL);
+        map.put(Tabs.HISTORY, Tabs.HISTORY);
+        map.put(Tabs.FAVICON, Tabs.FAVICON);
+        map.put(Tabs.LAST_USED, Tabs.LAST_USED);
+        map.put(Tabs.POSITION, Tabs.POSITION);
+        map.put(Clients.GUID, Clients.GUID);
+        map.put(Clients.NAME, Clients.NAME);
+        map.put(Clients.LAST_MODIFIED, Clients.LAST_MODIFIED);
+        map.put(Clients.DEVICE_TYPE, Clients.DEVICE_TYPE);
+        TABS_PROJECTION_MAP = Collections.unmodifiableMap(map);
+
+        map = new HashMap<String, String>();
+        map.put(Clients.GUID, Clients.GUID);
+        map.put(Clients.NAME, Clients.NAME);
+        map.put(Clients.LAST_MODIFIED, Clients.LAST_MODIFIED);
+        map.put(Clients.DEVICE_TYPE, Clients.DEVICE_TYPE);
+        CLIENTS_PROJECTION_MAP = Collections.unmodifiableMap(map);
+
+        map = new HashMap<>();
+        map.put(Clients.GUID, projectColumn(TABLE_CLIENTS, Clients.GUID) + " AS guid");
+        map.put(Clients.NAME, projectColumn(TABLE_CLIENTS, Clients.NAME) + " AS name");
+        map.put(Clients.LAST_MODIFIED, projectColumn(TABLE_CLIENTS, Clients.LAST_MODIFIED) + " AS last_modified");
+        map.put(Clients.DEVICE_TYPE, projectColumn(TABLE_CLIENTS, Clients.DEVICE_TYPE) + " AS device_type");
+        // last_used is the max of the tab last_used times, or if there are no tabs,
+        // the client's last_modified time.
+        map.put(Tabs.LAST_USED, "COALESCE(MAX(" + projectColumn(TABLE_TABS, Tabs.LAST_USED) + "), " + projectColumn(TABLE_CLIENTS, Clients.LAST_MODIFIED) + ") AS last_used");
+        CLIENTS_RECENCY_PROJECTION_MAP = Collections.unmodifiableMap(map);
+    }
+
+    private static final String projectColumn(String table, String column) {
+        return table + "." + column;
+    }
+
+    private static final String selectColumn(String table, String column) {
+        return projectColumn(table, column) + " = ?";
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        final int match = URI_MATCHER.match(uri);
+
+        trace("Getting URI type: " + uri);
+
+        switch (match) {
+            case TABS:
+                trace("URI is TABS: " + uri);
+                return Tabs.CONTENT_TYPE;
+
+            case TABS_ID:
+                trace("URI is TABS_ID: " + uri);
+                return Tabs.CONTENT_ITEM_TYPE;
+
+            case CLIENTS:
+                trace("URI is CLIENTS: " + uri);
+                return Clients.CONTENT_TYPE;
+
+            case CLIENTS_ID:
+                trace("URI is CLIENTS_ID: " + uri);
+                return Clients.CONTENT_ITEM_TYPE;
+        }
+
+        debug("URI has unrecognized type: " + uri);
+
+        return null;
+    }
+
+    @Override
+    @SuppressWarnings("fallthrough")
+    public int deleteInTransaction(Uri uri, String selection, String[] selectionArgs) {
+        trace("Calling delete in transaction on URI: " + uri);
+
+        final int match = URI_MATCHER.match(uri);
+        int deleted = 0;
+
+        switch (match) {
+            case CLIENTS_ID:
+                trace("Delete on CLIENTS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_CLIENTS, Clients._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+                // fall through
+            case CLIENTS:
+                trace("Delete on CLIENTS: " + uri);
+                deleted = deleteValues(uri, selection, selectionArgs, TABLE_CLIENTS);
+                break;
+
+            case TABS_ID:
+                trace("Delete on TABS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_TABS, Tabs._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+                // fall through
+            case TABS:
+                trace("Deleting on TABS: " + uri);
+                deleted = deleteValues(uri, selection, selectionArgs, TABLE_TABS);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown delete URI " + uri);
+        }
+
+        debug("Deleted " + deleted + " rows for URI: " + uri);
+
+        return deleted;
+    }
+
+    @Override
+    public Uri insertInTransaction(Uri uri, ContentValues values) {
+        trace("Calling insert in transaction on URI: " + uri);
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        int match = URI_MATCHER.match(uri);
+        long id = -1;
+
+        switch (match) {
+            case CLIENTS:
+                String guid = values.getAsString(Clients.GUID);
+                debug("Inserting client in database with GUID: " + guid);
+                id = db.insertOrThrow(TABLE_CLIENTS, Clients.GUID, values);
+                break;
+
+            case TABS:
+                String url = values.getAsString(Tabs.URL);
+                debug("Inserting tab in database with URL: " + url);
+                id = db.insertOrThrow(TABLE_TABS, Tabs.TITLE, values);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown insert URI " + uri);
+        }
+
+        debug("Inserted ID in database: " + id);
+
+        if (id >= 0)
+            return ContentUris.withAppendedId(uri, id);
+
+        return null;
+    }
+
+    @Override
+    public int updateInTransaction(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        trace("Calling update in transaction on URI: " + uri);
+
+        int match = URI_MATCHER.match(uri);
+        int updated = 0;
+
+        switch (match) {
+            case CLIENTS_ID:
+                trace("Update on CLIENTS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_CLIENTS, Clients._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+                // fall through
+            case CLIENTS:
+                trace("Update on CLIENTS: " + uri);
+                updated = updateValues(uri, values, selection, selectionArgs, TABLE_CLIENTS);
+                break;
+
+            case TABS_ID:
+                trace("Update on TABS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_TABS, Tabs._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+                // fall through
+            case TABS:
+                trace("Update on TABS: " + uri);
+                updated = updateValues(uri, values, selection, selectionArgs, TABLE_TABS);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown update URI " + uri);
+        }
+
+        debug("Updated " + updated + " rows for URI: " + uri);
+
+        return updated;
+    }
+
+    @Override
+    @SuppressWarnings("fallthrough")
+    public Cursor query(Uri uri, String[] projection, String selection,
+            String[] selectionArgs, String sortOrder) {
+        SQLiteDatabase db = getReadableDatabase(uri);
+        final int match = URI_MATCHER.match(uri);
+
+        String groupBy = null;
+        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
+        String limit = uri.getQueryParameter(BrowserContract.PARAM_LIMIT);
+
+        switch (match) {
+            case TABS_ID:
+                trace("Query is on TABS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_TABS, Tabs._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+                // fall through
+            case TABS:
+                trace("Query is on TABS: " + uri);
+                if (TextUtils.isEmpty(sortOrder)) {
+                    sortOrder = DEFAULT_TABS_SORT_ORDER;
+                } else {
+                    debug("Using sort order " + sortOrder + ".");
+                }
+
+                qb.setProjectionMap(TABS_PROJECTION_MAP);
+                qb.setTables(TABLE_TABS + " LEFT OUTER JOIN " + TABLE_CLIENTS + " ON (" + TABLE_TABS + "." + Tabs.CLIENT_GUID + " = " + TABLE_CLIENTS + "." + Clients.GUID + ")");
+                break;
+
+            case CLIENTS_ID:
+                trace("Query is on CLIENTS_ID: " + uri);
+                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_CLIENTS, Clients._ID));
+                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
+                        new String[] { Long.toString(ContentUris.parseId(uri)) });
+                // fall through
+            case CLIENTS:
+                trace("Query is on CLIENTS: " + uri);
+                if (TextUtils.isEmpty(sortOrder)) {
+                    sortOrder = DEFAULT_CLIENTS_SORT_ORDER;
+                } else {
+                    debug("Using sort order " + sortOrder + ".");
+                }
+
+                qb.setProjectionMap(CLIENTS_PROJECTION_MAP);
+                qb.setTables(TABLE_CLIENTS);
+                break;
+
+            case CLIENTS_RECENCY:
+                trace("Query is on CLIENTS_RECENCY: " + uri);
+                if (TextUtils.isEmpty(sortOrder)) {
+                    sortOrder = DEFAULT_CLIENTS_RECENCY_SORT_ORDER;
+                } else {
+                    debug("Using sort order " + sortOrder + ".");
+                }
+
+                final long oneWeekAgo = System.currentTimeMillis() - ONE_WEEK_IN_MILLISECONDS;
+                final long threeWeeksAgo = System.currentTimeMillis() - THREE_WEEKS_IN_MILLISECONDS;
+
+                final String excludeStaleClientsTable = String.format(EXCLUDE_STALE_CLIENTS_SUBQUERY, oneWeekAgo, threeWeeksAgo);
+
+                qb.setProjectionMap(CLIENTS_RECENCY_PROJECTION_MAP);
+
+                // Use a subquery to quietly exclude stale duplicate client records.
+                qb.setTables(excludeStaleClientsTable + " AS " + TABLE_CLIENTS + " LEFT OUTER JOIN " + TABLE_TABS +
+                        " ON (" + projectColumn(TABLE_CLIENTS, Clients.GUID) +
+                        " = " + projectColumn(TABLE_TABS, Tabs.CLIENT_GUID) + ")");
+                groupBy = projectColumn(TABLE_CLIENTS, Clients.GUID);
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Unknown query URI " + uri);
+        }
+
+        trace("Running built query.");
+        final Cursor cursor = qb.query(db, projection, selection, selectionArgs, groupBy, null, sortOrder, limit);
+        cursor.setNotificationUri(getContext().getContentResolver(), BrowserContract.TABS_AUTHORITY_URI);
+
+        return cursor;
+    }
+
+    int updateValues(Uri uri, ContentValues values, String selection, String[] selectionArgs, String table) {
+        trace("Updating tabs on URI: " + uri);
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        beginWrite(db);
+        return db.update(table, values, selection, selectionArgs);
+    }
+
+    int deleteValues(Uri uri, String selection, String[] selectionArgs, String table) {
+        debug("Deleting tabs for URI: " + uri);
+
+        final SQLiteDatabase db = getWritableDatabase(uri);
+        beginWrite(db);
+        return db.delete(table, selection, selectionArgs);
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/URLMetadata.java

@@ -0,0 +1,25 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.mozilla.gecko.db;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.json.JSONObject;
+
+import org.mozilla.gecko.annotation.RobocopTarget;
+
+import android.content.ContentResolver;
+
+@RobocopTarget
+public interface URLMetadata {
+    public Map<String, Object> fromJSON(JSONObject obj);
+    public Map<String, Map<String, Object>> getForURLs(final ContentResolver cr,
+                                                       final Collection<String> urls,
+                                                       final List<String> columns);
+    public void save(final ContentResolver cr, final Map<String, Object> data);
+}

mobile/android/base/java/org/mozilla/gecko/db/URLMetadataTable.java

@@ -0,0 +1,92 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+package org.mozilla.gecko.db;
+
+import org.mozilla.gecko.db.BrowserContract.Bookmarks;
+import org.mozilla.gecko.db.BrowserContract.History;
+
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+
+// Holds metadata info about urls. Supports some helper functions for getting back a HashMap of key value data.
+public class URLMetadataTable extends BaseTable {
+    private static final String LOGTAG = "GeckoURLMetadataTable";
+
+    private static final String TABLE = "metadata"; // Name of the table in the db
+    private static final int TABLE_ID_NUMBER = BrowserProvider.METADATA;
+
+    // Uri for querying this table
+    public static final Uri CONTENT_URI = Uri.withAppendedPath(BrowserContract.AUTHORITY_URI, "metadata");
+
+    // Columns in the table
+    public static final String ID_COLUMN = "id";
+    public static final String URL_COLUMN = "url";
+    public static final String TILE_IMAGE_URL_COLUMN = "tileImage";
+    public static final String TILE_COLOR_COLUMN = "tileColor";
+    public static final String TOUCH_ICON_COLUMN = "touchIcon";
+
+    URLMetadataTable() { }
+
+    @Override
+    protected String getTable() {
+        return TABLE;
+    }
+
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        String create = "CREATE TABLE " + TABLE + " (" +
+            ID_COLUMN + " INTEGER PRIMARY KEY, " +
+            URL_COLUMN + " TEXT NON NULL UNIQUE, " +
+            TILE_IMAGE_URL_COLUMN + " STRING, " +
+            TILE_COLOR_COLUMN + " STRING, " +
+            TOUCH_ICON_COLUMN + " STRING);";
+        db.execSQL(create);
+    }
+
+    private void upgradeDatabaseFrom26To27(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE +
+                   " ADD COLUMN " + TOUCH_ICON_COLUMN + " STRING");
+    }
+
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        // This table was added in v21 of the db. Force its creation if we're coming from an earlier version
+        if (newVersion >= 21 && oldVersion < 21) {
+            onCreate(db);
+            return;
+        }
+
+        // Removed the redundant metadata_url_idx index in version 26
+        if (newVersion >= 26 && oldVersion < 26) {
+            db.execSQL("DROP INDEX IF EXISTS metadata_url_idx");
+        }
+        if (newVersion >= 27 && oldVersion < 27) {
+            upgradeDatabaseFrom26To27(db);
+        }
+    }
+
+    @Override
+    public Table.ContentProviderInfo[] getContentProviderInfo() {
+        return new Table.ContentProviderInfo[] {
+            new Table.ContentProviderInfo(TABLE_ID_NUMBER, TABLE)
+        };
+    }
+
+    public int deleteUnused(final SQLiteDatabase db) {
+        final String selection = URL_COLUMN + " NOT IN " +
+                                 "(SELECT " + History.URL +
+                                 " FROM " + History.TABLE_NAME +
+                                 " WHERE " + History.IS_DELETED + " = 0" +
+                                 " UNION " +
+                                 " SELECT " + Bookmarks.URL +
+                                 " FROM " + Bookmarks.TABLE_NAME +
+                                 " WHERE " + Bookmarks.IS_DELETED + " = 0 " +
+                                 " AND " + Bookmarks.URL + " IS NOT NULL)";
+
+        return db.delete(getTable(), selection, null);
+    }
+}

mobile/android/base/java/org/mozilla/gecko/db/UrlAnnotations.java

@@ -0,0 +1,51 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.db;
+
+import android.content.ContentResolver;
+import android.database.Cursor;
+import org.mozilla.gecko.annotation.RobocopTarget;
+import org.mozilla.gecko.feeds.subscriptions.FeedSubscription;
+
+public interface UrlAnnotations {
+    @RobocopTarget void insertAnnotation(ContentResolver cr, String url, String key, String value);
+
+    Cursor getScreenshots(ContentResolver cr);
+    void insertScreenshot(ContentResolver cr, String pageUrl, String screenshotPath);
+
+    Cursor getFeedSubscriptions(ContentResolver cr);
+    Cursor getWebsitesWithFeedUrl(ContentResolver cr);
+    void deleteFeedUrl(ContentResolver cr, String websiteUrl);
+    boolean hasWebsiteForFeedUrl(ContentResolver cr, String feedUrl);
+    void deleteFeedSubscription(ContentResolver cr, FeedSubscription subscription);
+    void updateFeedSubscription(ContentResolver cr, FeedSubscription subscription);
+    boolean hasFeedSubscription(ContentResolver cr, String feedUrl);
+    void insertFeedSubscription(ContentResolver cr, FeedSubscription subscription);
+    boolean hasFeedUrlForWebsite(ContentResolver cr, String websiteUrl);
+    void insertFeedUrl(ContentResolver cr, String originUrl, String feedUrl);
+
+    void insertReaderViewUrl(ContentResolver cr, String pageURL);
+    void deleteReaderViewUrl(ContentResolver cr, String pageURL);
+
+    /**
+     * Did the user ever interact with this URL in regards to home screen shortcuts?
+     *
+     * @return true if the user has created a home screen shortcut or declined to create one in the
+     *         past. This method will still return true if the shortcut has been removed from the
+     *         home screen by the user.
+     */
+    boolean hasAcceptedOrDeclinedHomeScreenShortcut(ContentResolver cr, String url);
+
+    /**
+     * Insert an indication that the user has interacted with this URL in regards to home screen
+     * shortcuts.
+     *
+     * @param hasCreatedShortCut True if a home screen shortcut has been created for this URL. False
+     *                           if the user has actively declined to create a shortcut for this URL.
+     */
+    void insertHomeScreenShortcut(ContentResolver cr, String url, boolean hasCreatedShortCut);
+
+    int getAnnotationCount(ContentResolver cr, BrowserContract.UrlAnnotations.Key key);
+}