Make the externally connectable browser test clobber all of the builtins,

chrome/renderer/resources/extensions/ad_view.js

 // Copyright 2013 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.
 
 // Shim that simulates a <adview> tag via Mutation Observers.
 //
 // The actual tag is implemented via the browser plugin. The internals of this
 // are hidden via Shadow DOM.
 
 // TODO(rpaquay): This file is currently very similar to "web_view.js". Do we
@@ skipping 142 matching lines @@
 
 /**
  * @private
  */
 AdView.prototype.setupAdviewNodeMethods_ = function() {
   // this.browserPluginNode_[apiMethod] are not necessarily defined immediately
   // after the shadow object is appended to the shadow root.
   var self = this;
   $Array.forEach(AD_VIEW_API_METHODS, function(apiMethod) {
     self.adviewNode_[apiMethod] = function(var_args) {
-      return self.browserPluginNode_[apiMethod].apply(
+      return $Function.apply(self.browserPluginNode_[apiMethod],
         self.browserPluginNode_, arguments);
     };
   }, this);
 }
 
 /**
  * @private
  */
 AdView.prototype.setupAdviewNodeObservers_ = function() {
   // Map attribute modifications on the <adview> tag to property changes in
@@ skipping 291 matching lines @@
   // Dispatch event.
   this.adviewNode_.dispatchEvent(evt);
 }
 
 //
 // Hook up <adview> tag creation in DOM.
 //
 window.addEventListener('DOMContentLoaded', function() {
   watchForTag('ADVIEW', function(addedNode) { new AdView(addedNode); });
 });