diff -r 000000000000 -r 6474c204b198 mobile/android/base/gfx/PanZoomController.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/gfx/PanZoomController.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,48 @@
+/* -*- 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.gfx;
+
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.EventDispatcher;
+
+import android.graphics.PointF;
+import android.view.KeyEvent;
+import android.view.MotionEvent;
+import android.view.View;
+
+public interface PanZoomController {
+    // The distance the user has to pan before we recognize it as such (e.g. to avoid 1-pixel pans
+    // between the touch-down and touch-up of a click). In units of density-independent pixels.
+    public static final float PAN_THRESHOLD = 1/16f * GeckoAppShell.getDpi();
+
+    // Threshold for sending touch move events to content
+    public static final float CLICK_THRESHOLD = 1/50f * GeckoAppShell.getDpi();
+
+    static class Factory {
+        static PanZoomController create(PanZoomTarget target, View view, EventDispatcher dispatcher) {
+            return new JavaPanZoomController(target, view, dispatcher);
+        }
+    }
+
+    public void destroy();
+
+    public boolean onTouchEvent(MotionEvent event);
+    public boolean onMotionEvent(MotionEvent event);
+    public boolean onKeyEvent(KeyEvent event);
+    public void notifyDefaultActionPrevented(boolean prevented);
+
+    public boolean getRedrawHint();
+    public PointF getVelocityVector();
+
+    public void pageRectUpdated();
+    public void abortPanning();
+    public void abortAnimation();
+
+    public void setOverScrollMode(int overscrollMode);
+    public int getOverScrollMode();
+
+    public void setOverscrollHandler(final Overscroll controller);
+}