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

mobile/android/tests/browser/chrome/head_search.js

@@ -0,0 +1,46 @@
+// Bits and pieces copied from toolkit/components/search/tests/xpcshell/head_search.js
+
+var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+
+/**
+ * Adds test engines and returns a promise resolved when they are installed.
+ *
+ * The engines are added in the given order.
+ *
+ * @param aItems
+ *        Array of objects with the following properties:
+ *        {
+ *          name: Engine name, used to wait for it to be loaded.
+ *          details: Array containing the parameters of addEngineWithDetails,
+ *                   except for the engine name.  Alternative to xmlFileName.
+ *        }
+ */
+var addTestEngines = Task.async(function* (aItems) {
+  let engines = [];
+
+  for (let item of aItems) {
+    yield new Promise((resolve, reject) => {
+      Services.obs.addObserver(function obs(subject, topic, data) {
+        try {
+          let engine = subject.QueryInterface(Ci.nsISearchEngine);
+          if (data != "engine-added" || engine.name != item.name) {
+            return;
+          }
+
+          Services.obs.removeObserver(obs, "browser-search-engine-modified");
+          engines.push(engine);
+          resolve();
+        } catch (ex) {
+          reject(ex);
+        }
+      }, "browser-search-engine-modified", false);
+
+      Services.search.addEngineWithDetails(item.name, ...item.details);
+    });
+  }
+
+  return engines;
+});