diff -r 000000000000 -r 6474c204b198 mobile/android/base/util/UiAsyncTask.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/util/UiAsyncTask.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,86 @@
+/* -*- 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.util;
+
+import android.os.Handler;
+import android.os.Looper;
+
+/**
+ * Executes a background task and publishes the result on the UI thread.
+ *
+ * The standard {@link android.os.AsyncTask} only runs onPostExecute on the
+ * thread it is constructed on, so this is a convenience class for creating
+ * tasks off the UI thread.
+ */
+public abstract class UiAsyncTask<Params, Progress, Result> {
+    private volatile boolean mCancelled = false;
+    private final Handler mBackgroundThreadHandler;
+    private static Handler sHandler;
+
+    /**
+     * Creates a new asynchronous task.
+     *
+     * @param backgroundThreadHandler the handler to execute the background task on
+     */
+    public UiAsyncTask(Handler backgroundThreadHandler) {
+        mBackgroundThreadHandler = backgroundThreadHandler;
+    }
+
+    private static synchronized Handler getUiHandler() {
+        if (sHandler == null) {
+            sHandler = new Handler(Looper.getMainLooper());
+        }
+        return sHandler;
+    }
+
+    private final class BackgroundTaskRunnable implements Runnable {
+        private Params[] mParams;
+
+        public BackgroundTaskRunnable(Params... params) {
+            mParams = params;
+        }
+
+        @Override
+        public void run() {
+            final Result result = doInBackground(mParams);
+
+            getUiHandler().post(new Runnable() {
+                @Override
+                public void run() {
+                    if (mCancelled)
+                        onCancelled();
+                    else
+                        onPostExecute(result);
+                }
+            });
+        }
+    }
+
+    public final void execute(final Params... params) {
+        getUiHandler().post(new Runnable() {
+            @Override
+            public void run() {
+                onPreExecute();
+                mBackgroundThreadHandler.post(new BackgroundTaskRunnable(params));
+            }
+        });
+    }
+
+    @SuppressWarnings({"UnusedParameters"})
+    public final boolean cancel(boolean mayInterruptIfRunning) {
+        mCancelled = true;
+        return mCancelled;
+    }
+
+    public final boolean isCancelled() {
+        return mCancelled;
+    }
+
+    protected void onPreExecute() { }
+    protected void onPostExecute(Result result) { }
+    protected void onCancelled() { }
+    protected abstract Result doInBackground(Params... params);
+}