pt 1 in reviving the android build (copied from pm 28a1, wish me luck)

mobile/android/javaaddons/java/org/mozilla/javaaddons/JavaAddonInterfaceV1.java

@@ -0,0 +1,51 @@
+/* -*- 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.javaaddons;
+
+import android.content.Context;
+import org.json.JSONObject;
+
+public interface JavaAddonInterfaceV1 {
+    /**
+     * Callback interface for Gecko requests.
+     * <p/>
+     * For each instance of EventCallback, exactly one of sendResponse, sendError, must be called to prevent observer leaks.
+     * If more than one send* method is called, or if a single send method is called multiple times, an
+     * {@link IllegalStateException} will be thrown.
+     */
+    interface EventCallback {
+        /**
+         * Sends a success response with the given data.
+         *
+         * @param response The response data to send to Gecko. Can be any of the types accepted by
+         *                 JSONObject#put(String, Object).
+         */
+        public void sendSuccess(Object response);
+
+        /**
+         * Sends an error response with the given data.
+         *
+         * @param response The response data to send to Gecko. Can be any of the types accepted by
+         *                 JSONObject#put(String, Object).
+         */
+        public void sendError(Object response);
+    }
+
+    interface EventDispatcher {
+        void registerEventListener(EventListener listener, String... events);
+        void unregisterEventListener(EventListener listener);
+
+        void sendRequestToGecko(String event, JSONObject message, RequestCallback callback);
+    }
+
+    interface EventListener {
+        public void handleMessage(final Context context, final String event, final JSONObject message, final EventCallback callback);
+    }
+
+    interface RequestCallback {
+        void onResponse(final Context context, JSONObject jsonObject);
+    }
+}