Fix bump-scroll.

remoting/webapp/client_session.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
  * Class handling creation and teardown of a remoting client session.
  *
  * The ClientSession class controls lifetime of the client plugin
  * object and provides the plugin with the functionality it needs to
@@ skipping 1312 matching lines @@
  * scrollLeft properties don't work.
  * @param {number} dx The amount by which to scroll horizontally. Positive to
  *     scroll right; negative to scroll left.
  * @param {number} dy The amount by which to scroll vertically. Positive to
  *     scroll down; negative to scroll up.
  * @return {boolean} True if the requested scroll had no effect because both
  *     vertical and horizontal edges of the screen have been reached.
  * @private
  */
 remoting.ClientSession.prototype.scroll_ = function(dx, dy) {
-  var plugin = this.plugin_.element();
-  var style = plugin.style;
-
   /**
    * Helper function for x- and y-scrolling
    * @param {number|string} curr The current margin, eg. "10px".
    * @param {number} delta The requested scroll amount.
    * @param {number} windowBound The size of the window, in pixels.
    * @param {number} pluginBound The size of the plugin, in pixels.
    * @param {{stop: boolean}} stop Reference parameter used to indicate when
    *     the scroll has reached one of the edges and can be stopped in that
    *     direction.
    * @return {string} The new margin value.
    */
   var adjustMargin = function(curr, delta, windowBound, pluginBound, stop) {
     var minMargin = Math.min(0, windowBound - pluginBound);
     var result = (curr ? parseFloat(curr) : 0) - delta;
     result = Math.min(0, Math.max(minMargin, result));
     stop.stop = (result == 0 || result == minMargin);
     return result + 'px';
   };
 
+  var plugin = this.plugin_.element();
+  var style = this.container_.style;
+
   var stopX = { stop: false };
   var clientArea = this.getClientArea_();
   style.marginLeft = adjustMargin(style.marginLeft, dx, clientArea.width,
       this.pluginWidthForBumpScrollTesting || plugin.clientWidth, stopX);
 
   var stopY = { stop: false };
   style.marginTop = adjustMargin(
       style.marginTop, dy, clientArea.height,
       this.pluginHeightForBumpScrollTesting || plugin.clientHeight, stopY);
   return stopX.stop && stopY.stop;
 };
 
 remoting.ClientSession.prototype.resetScroll_ = function() {
-  if (this.plugin_) {
-    var plugin = this.plugin_.element();
-    plugin.style.marginTop = '0px';
-    plugin.style.marginLeft = '0px';
-  }
+  this.container_.style.marginTop = '0px';
+  this.container_.style.marginLeft = '0px';
 };
 
 /**
  * Enable or disable bump-scrolling. When disabling bump scrolling, also reset
  * the scroll offsets to (0, 0).
  * @private
  * @param {boolean} enable True to enable bump-scrolling, false to disable it.
  */
 remoting.ClientSession.prototype.enableBumpScroll_ = function(enable) {
   var element = /*@type{HTMLElement} */ document.documentElement;
@@ skipping 142 matching lines @@
     this.mouseCursorOverlay_.style.marginLeft = '-' + hotspotX + 'px';
     this.mouseCursorOverlay_.style.marginTop = '-' + hotspotY + 'px';
     this.mouseCursorOverlay_.src = url;
   }
 };
 
 /**
  * @return {{top: number, left:number}} The top-left corner of the plugin.
  */
 remoting.ClientSession.prototype.getPluginPositionForTesting = function() {
-  var plugin = this.plugin_.element();
-  var style = plugin.style;
+  var style = this.container_.style;
   return {
     top: parseFloat(style.marginTop),
     left: parseFloat(style.marginLeft)
   };
 };
 
 /**
  * Send a Cast extension message to the host.
  * @param {Object} data The cast message data.
  */
@@ skipping 66 matching lines @@
  * @param {string} data Contents of the extension message.
  * @return {boolean} True if the message was recognized, false otherwise.
  */
 remoting.ClientSession.prototype.handleExtensionMessage =
     function(type, data) {
   if (this.videoFrameRecorder_) {
     return this.videoFrameRecorder_.handleMessage(type, data);
   }
   return false;
 }