<webview>: Implement declarativeWebRequest API

chrome/renderer/resources/extensions/web_view_experimental.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 extension to provide permission request API (and possibly other future
 // experimental APIs) for <webview> tag.
 // See web_view.js for details.
 //
 // We want to control the permission API feature in <webview> separately from
 // the <webview> feature itself. <webview> is available in stable channel, but
@@ skipping 12 matching lines @@
       webViewInternal.handleDialogEvent_(event, webViewEvent);
     },
     evt: CreateEvent('webview.onDialog'),
     fields: ['defaultPromptText', 'messageText', 'messageType', 'url']
   }
 };
 
 /**
  * @private
  */
-WebViewInternal.prototype.maybeAttachWebRequestEventToWebview_ =
-    function(eventName, webRequestEvent) {
+WebViewInternal.prototype.maybeAttachWebRequestEventToObject_ =
+    function(obj, eventName, webRequestEvent) {
   Object.defineProperty(
-      this.webviewNode_,
+      obj,
       eventName,
       {
         get: webRequestEvent,
         enumerable: true
       }
   );
 };
 
 /**
  * @private
@@ skipping 124 matching lines @@
   };
 
   proto.isUserAgentOverridden = function() {
     return this.internal_(secret).isUserAgentOverridden_();
   };
 
   proto.setUserAgentOverride = function(userAgentOverride) {
     this.internal_(secret).setUserAgentOverride_(userAgentOverride);
   };
 };