Fix cross-frame horizontal scrolling on the uber page.

chrome/browser/resources/uber/uber_utils.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview A collection of utility methods for UberPage and its contained
  *     pages.
  */
 
 cr.define('uber', function() {
@@ skipping 21 matching lines @@
 
     window.addEventListener('message', handleWindowMessage);
   }
 
   /**
    * Handles scroll events on the document. This adjusts the position of all
    * headers and updates the parent frame when the page is scrolled.
    * @private
    */
   function handleScroll() {
-    var offset = document.body.scrollLeft * -1;
+    var offset = document.documentElement.scrollLeft * -1;
     for (var i = 0; i < headerElements.length; i++) {
       // As a workaround for http://crbug.com/231830, set the transform to
       // 'none' rather than 0px.
       headerElements[i].style.webkitTransform = offset ?
           'translateX(' + offset + 'px)' : 'none';
     }
 
-    invokeMethodOnParent('adjustToScroll', document.body.scrollLeft);
+    invokeMethodOnParent('adjustToScroll', document.documentElement.scrollLeft);
   };
 
   /**
    * Handles 'message' events on window.
    * @param {Event} e The message event.
    */
   function handleWindowMessage(e) {
     if (e.data.method === 'frameSelected')
       handleFrameSelected();
     else if (e.data.method === 'mouseWheel')
       handleMouseWheel(e.data.params);
   }
 
   /**
    * This is called when a user selects this frame via the navigation bar
    * frame (and is triggered via postMessage() from the uber page).
    * @private
    */
   function handleFrameSelected() {
-    document.body.scrollLeft = 0;
+    document.documentElement.scrollLeft = 0;
   }
 
   /**
    * Called when a user mouse wheels (or trackpad scrolls) over the nav frame.
    * The wheel event is forwarded here and we scroll the body.
    * There's no way to figure out the actual scroll amount for a given delta.
    * It differs for every platform and even initWebKitWheelEvent takes a
    * pixel amount instead of a wheel delta. So we just choose something
    * reasonable and hope no one notices the difference.
    * @param {Object} params A structure that holds wheel deltas in X and Y.
@@ skipping 30 matching lines @@
     var data = {method: method, params: opt_params};
     targetWindow.postMessage(data, opt_url ? opt_url : '*');
   }
 
   return {
     invokeMethodOnParent: invokeMethodOnParent,
     invokeMethodOnWindow: invokeMethodOnWindow,
     onContentFrameLoaded: onContentFrameLoaded,
   };
 });