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diff --git a/testing/marionette/harness/marionette_harness/www/shim.js b/testing/marionette/harness/marionette_harness/www/shim.js
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+/**
+* mouse_event_shim.js: generate mouse events from touch events.
+*
+* This library listens for touch events and generates mousedown, mousemove
+* mouseup, and click events to match them. It captures and dicards any
+* real mouse events (non-synthetic events with isTrusted true) that are
+* send by gecko so that there are not duplicates.
+*
+* This library does emit mouseover/mouseout and mouseenter/mouseleave
+* events. You can turn them off by setting MouseEventShim.trackMouseMoves to
+* false. This means that mousemove events will always have the same target
+* as the mousedown even that began the series. You can also call
+* MouseEventShim.setCapture() from a mousedown event handler to prevent
+* mouse tracking until the next mouseup event.
+*
+* This library does not support multi-touch but should be sufficient
+* to do drags based on mousedown/mousemove/mouseup events.
+*
+* This library does not emit dblclick events or contextmenu events
+*/
+
+'use strict';
+
+(function() {
+  // Make sure we don't run more than once
+  if (MouseEventShim)
+    return;
+
+  // Bail if we're not on running on a platform that sends touch
+  // events. We don't need the shim code for mouse events.
+  try {
+    document.createEvent('TouchEvent');
+  } catch (e) {
+    return;
+  }
+
+  var starttouch; // The Touch object that we started with
+  var target; // The element the touch is currently over
+  var emitclick; // Will we be sending a click event after mouseup?
+
+  // Use capturing listeners to discard all mouse events from gecko
+  window.addEventListener('mousedown', discardEvent, true);
+  window.addEventListener('mouseup', discardEvent, true);
+  window.addEventListener('mousemove', discardEvent, true);
+  window.addEventListener('click', discardEvent, true);
+
+  function discardEvent(e) {
+    if (e.isTrusted) {
+      e.stopImmediatePropagation(); // so it goes no further
+      if (e.type === 'click')
+        e.preventDefault(); // so it doesn't trigger a change event
+    }
+  }
+
+  // Listen for touch events that bubble up to the window.
+  // If other code has called stopPropagation on the touch events
+  // then we'll never see them. Also, we'll honor the defaultPrevented
+  // state of the event and will not generate synthetic mouse events
+  window.addEventListener('touchstart', handleTouchStart);
+  window.addEventListener('touchmove', handleTouchMove);
+  window.addEventListener('touchend', handleTouchEnd);
+  window.addEventListener('touchcancel', handleTouchEnd); // Same as touchend
+
+  function handleTouchStart(e) {
+    // If we're already handling a touch, ignore this one
+    if (starttouch)
+      return;
+
+    // Ignore any event that has already been prevented
+    if (e.defaultPrevented)
+      return;
+
+    // Sometimes an unknown gecko bug causes us to get a touchstart event
+    // for an iframe target that we can't use because it is cross origin.
+    // Don't start handling a touch in that case
+    try {
+      e.changedTouches[0].target.ownerDocument;
+    }
+    catch (e) {
+      // Ignore the event if we can't see the properties of the target
+      return;
+    }
+
+    // If there is more than one simultaneous touch, ignore all but the first
+    starttouch = e.changedTouches[0];
+    target = starttouch.target;
+    emitclick = true;
+
+    // Move to the position of the touch
+    emitEvent('mousemove', target, starttouch);
+
+    // Now send a synthetic mousedown
+    var result = emitEvent('mousedown', target, starttouch);
+
+    // If the mousedown was prevented, pass that on to the touch event.
+    // And remember not to send a click event
+    if (!result) {
+      e.preventDefault();
+      emitclick = false;
+    }
+  }
+
+  function handleTouchEnd(e) {
+    if (!starttouch)
+      return;
+
+    // End a MouseEventShim.setCapture() call
+    if (MouseEventShim.capturing) {
+      MouseEventShim.capturing = false;
+      MouseEventShim.captureTarget = null;
+    }
+
+    for (var i = 0; i < e.changedTouches.length; i++) {
+      var touch = e.changedTouches[i];
+      // If the ended touch does not have the same id, skip it
+      if (touch.identifier !== starttouch.identifier)
+        continue;
+
+      emitEvent('mouseup', target, touch);
+
+      // If target is still the same element we started and the touch did not
+      // move more than the threshold and if the user did not prevent
+      // the mousedown, then send a click event, too.
+      if (emitclick)
+        emitEvent('click', starttouch.target, touch);
+
+      starttouch = null;
+      return;
+    }
+  }
+
+  function handleTouchMove(e) {
+    if (!starttouch)
+      return;
+
+    for (var i = 0; i < e.changedTouches.length; i++) {
+      var touch = e.changedTouches[i];
+      // If the ended touch does not have the same id, skip it
+      if (touch.identifier !== starttouch.identifier)
+        continue;
+
+      // Don't send a mousemove if the touchmove was prevented
+      if (e.defaultPrevented)
+        return;
+
+      // See if we've moved too much to emit a click event
+      var dx = Math.abs(touch.screenX - starttouch.screenX);
+      var dy = Math.abs(touch.screenY - starttouch.screenY);
+      if (dx > MouseEventShim.dragThresholdX ||
+          dy > MouseEventShim.dragThresholdY) {
+        emitclick = false;
+      }
+
+      var tracking = MouseEventShim.trackMouseMoves &&
+        !MouseEventShim.capturing;
+
+      if (tracking) {
+        // If the touch point moves, then the element it is over
+        // may have changed as well. Note that calling elementFromPoint()
+        // forces a layout if one is needed.
+        // XXX: how expensive is it to do this on each touchmove?
+        // Can we listen for (non-standard) touchleave events instead?
+        var oldtarget = target;
+        var newtarget = document.elementFromPoint(touch.clientX, touch.clientY);
+        if (newtarget === null) {
+          // this can happen as the touch is moving off of the screen, e.g.
+          newtarget = oldtarget;
+        }
+        if (newtarget !== oldtarget) {
+          leave(oldtarget, newtarget, touch); // mouseout, mouseleave
+          target = newtarget;
+        }
+      }
+      else if (MouseEventShim.captureTarget) {
+        target = MouseEventShim.captureTarget;
+      }
+
+      emitEvent('mousemove', target, touch);
+
+      if (tracking && newtarget !== oldtarget) {
+        enter(newtarget, oldtarget, touch); // mouseover, mouseenter
+      }
+    }
+  }
+
+  // Return true if element a contains element b
+  function contains(a, b) {
+    return (a.compareDocumentPosition(b) & 16) !== 0;
+  }
+
+  // A touch has left oldtarget and entered newtarget
+  // Send out all the events that are required
+  function leave(oldtarget, newtarget, touch) {
+    emitEvent('mouseout', oldtarget, touch, newtarget);
+
+    // If the touch has actually left oldtarget (and has not just moved
+    // into a child of oldtarget) send a mouseleave event. mouseleave
+    // events don't bubble, so we have to repeat this up the hierarchy.
+    for (var e = oldtarget; !contains(e, newtarget); e = e.parentNode) {
+      emitEvent('mouseleave', e, touch, newtarget);
+    }
+  }
+
+  // A touch has entered newtarget from oldtarget
+  // Send out all the events that are required.
+  function enter(newtarget, oldtarget, touch) {
+    emitEvent('mouseover', newtarget, touch, oldtarget);
+
+    // Emit non-bubbling mouseenter events if the touch actually entered
+    // newtarget and wasn't already in some child of it
+    for (var e = newtarget; !contains(e, oldtarget); e = e.parentNode) {
+      emitEvent('mouseenter', e, touch, oldtarget);
+    }
+  }
+
+  function emitEvent(type, target, touch, relatedTarget) {
+    var synthetic = document.createEvent('MouseEvents');
+    var bubbles = (type !== 'mouseenter' && type !== 'mouseleave');
+    var count =
+      (type === 'mousedown' || type === 'mouseup' || type === 'click') ? 1 : 0;
+
+    synthetic.initMouseEvent(type,
+                             bubbles, // canBubble
+                             true, // cancelable
+                             window,
+                             count, // detail: click count
+                             touch.screenX,
+                             touch.screenY,
+                             touch.clientX,
+                             touch.clientY,
+                             false, // ctrlKey: we don't have one
+                             false, // altKey: we don't have one
+                             false, // shiftKey: we don't have one
+                             false, // metaKey: we don't have one
+                             0, // we're simulating the left button
+                             relatedTarget || null);
+
+    try {
+      return target.dispatchEvent(synthetic);
+    }
+    catch (e) {
+      console.warn('Exception calling dispatchEvent', type, e);
+      return true;
+    }
+  }
+}());
+
+var MouseEventShim = {
+  // It is a known gecko bug that synthetic events have timestamps measured
+  // in microseconds while regular events have timestamps measured in
+  // milliseconds. This utility function returns a the timestamp converted
+  // to milliseconds, if necessary.
+  getEventTimestamp: function(e) {
+    if (e.isTrusted) // XXX: Are real events always trusted?
+      return e.timeStamp;
+    else
+      return e.timeStamp / 1000;
+  },
+
+  // Set this to false if you don't care about mouseover/out events
+  // and don't want the target of mousemove events to follow the touch
+  trackMouseMoves: true,
+
+  // Call this function from a mousedown event handler if you want to guarantee
+  // that the mousemove and mouseup events will go to the same element
+  // as the mousedown even if they leave the bounds of the element. This is
+  // like setting trackMouseMoves to false for just one drag. It is a
+  // substitute for event.target.setCapture(true)
+  setCapture: function(target) {
+    this.capturing = true; // Will be set back to false on mouseup
+    if (target)
+      this.captureTarget = target;
+  },
+
+  capturing: false,
+
+  // Keep these in sync with ui.dragThresholdX and ui.dragThresholdY prefs.
+  // If a touch ever moves more than this many pixels from its starting point
+  // then we will not synthesize a click event when the touch ends.
+  dragThresholdX: 25,
+  dragThresholdY: 25
+};