Enables bump scrolling browser test on the Chromoting Waterfall.

remoting/webapp/crd/js/desktop_viewport.js

 // Copyright 2015 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
  * Provides view port management utilities below for a desktop remoting session.
  * - Enabling bump scrolling
  * - Resizing the viewport to fit the host desktop
  * - Resizing the host desktop to fit the client viewport.
@@ skipping 74 matching lines @@
  * @return {boolean} True if resize-to-client is enabled; false otherwise.
  */
 remoting.DesktopViewport.prototype.getResizeToClient = function() {
   return this.hostOptions_.resizeToClient;
 };
 
 /**
  * @return {{top:number, left:number}} The top-left corner of the plugin.
  */
 remoting.DesktopViewport.prototype.getPluginPositionForTesting = function() {
-  var style = this.pluginContainer_.style;
+  /**
+   * @param {number|string} value
+   * @return {number}
+   */
+  function toFloat(value) {
+    var number = parseFloat(value);
+    return isNaN(number) ? 0 : number;
+  }
   return {
-    top: parseFloat(style.marginTop),
-    left: parseFloat(style.marginLeft)
+    top: toFloat(this.pluginContainer_.style.marginTop),
+    left: toFloat(this.pluginContainer_.style.marginLeft)
   };
 };
 
 /**
  * @param {number} width
  * @param {number} height
  */
 remoting.DesktopViewport.prototype.setPluginSizeForBumpScrollTesting =
     function(width, height) {
   this.pluginWidthForBumpScrollTesting_ = width;
@@ skipping 367 matching lines @@
   return { width: pluginWidth, height: pluginHeight };
 };
 
 /** @private */
 remoting.DesktopViewport.prototype.resetScroll_ = function() {
   this.pluginContainer_.style.marginTop = '0px';
   this.pluginContainer_.style.marginLeft = '0px';
 };
 
 }());