diff -r 000000000000 -r 6474c204b198 mobile/android/base/ScrollAnimator.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/ScrollAnimator.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,84 @@
+/* -*- 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;
+
+import java.util.Timer;
+import java.util.TimerTask;
+
+import org.mozilla.gecko.util.GamepadUtils;
+
+import android.view.InputDevice;
+import android.view.MotionEvent;
+import android.view.View;
+
+public class ScrollAnimator implements View.OnGenericMotionListener {
+    private Timer mScrollTimer;
+    private int mX;
+    private int mY;
+
+    // Assuming 60fps, this will make the view scroll once per frame
+    static final long MS_PER_FRAME = 1000 / 60;
+
+    // Maximum number of pixels that can be scrolled per frame
+    static final float MAX_SCROLL = 0.075f * GeckoAppShell.getDpi();
+
+    private class ScrollRunnable extends TimerTask {
+        private View mView;
+
+        public ScrollRunnable(View view) {
+            mView = view;
+        }
+
+        @Override
+        public final void run() {
+            mView.scrollBy(mX, mY);
+        }
+    }
+
+    @Override
+    public boolean onGenericMotion(View view, MotionEvent event) {
+        if ((event.getSource() & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
+            switch (event.getAction()) {
+            case MotionEvent.ACTION_MOVE:
+                // Cancel the animation if the joystick is in a neutral position
+                if (GamepadUtils.isValueInDeadZone(event, MotionEvent.AXIS_X) &&
+                        GamepadUtils.isValueInDeadZone(event, MotionEvent.AXIS_Y)) {
+                    if (mScrollTimer != null) {
+                        mScrollTimer.cancel();
+                        mScrollTimer = null;
+                    }
+                    return true;
+                }
+
+                // Scroll with a velocity relative to the screen DPI
+                mX = (int) (event.getAxisValue(MotionEvent.AXIS_X) * MAX_SCROLL);
+                mY = (int) (event.getAxisValue(MotionEvent.AXIS_Y) * MAX_SCROLL);
+
+                // Start the timer; the view will continue to scroll as long as
+                // the joystick is not in the deadzone.
+                if (mScrollTimer == null) {
+                    mScrollTimer = new Timer();
+                    ScrollRunnable task = new ScrollRunnable(view);
+                    mScrollTimer.scheduleAtFixedRate(task, 0, MS_PER_FRAME);
+                }
+
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Cancels the running scroll animation if it is in progress.
+     */
+    public void cancel() {
+        if (mScrollTimer != null) {
+            mScrollTimer.cancel();
+            mScrollTimer = null;
+        }
+    }
+}