Refactored the attributes modules of extension_view and web_view into guest_view_attributes.js.

extensions/renderer/resources/guest_view/guest_view_container.js

 // Copyright 2014 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.
 
 // This module implements the shared functionality for different guestview
 // containers, such as web_view, app_view, etc.
 
 var DocumentNatives = requireNative('document_natives');
 var GuestView = require('guestView').GuestView;
 var GuestViewInternalNatives = requireNative('guest_view_internal');
@@ skipping 150 matching lines @@
   params['elementHeight'] = parseInt(elementRect.height);
   return params;
 };
 
 GuestViewContainer.prototype.dispatchEvent = function(event) {
   return this.element.dispatchEvent(event);
 }
 
 // Implemented by the specific view type, if needed.
 GuestViewContainer.prototype.buildContainerParams = function() { return {}; };
-GuestViewContainer.prototype.handleAttributeMutation = function() {};
+// TODO(paulmeyer): remove once all view types use attribute objects.
+GuestViewContainer.prototype.handleAttributeMutation = function(
+    attributeName, oldValue, newValue) {};
 GuestViewContainer.prototype.onElementAttached = function() {};
-GuestViewContainer.prototype.onElementDetached = function() {
-  this.guest.destroy();
-};
+GuestViewContainer.prototype.onElementDetached = function() {};
 
 // Registers the browser plugin <object> custom element. |viewType| is the
 // name of the specific guestview container (e.g. 'webview').
 function registerBrowserPluginElement(viewType) {
   var proto = Object.create(HTMLObjectElement.prototype);
 
   proto.createdCallback = function() {
     this.setAttribute('type', 'application/browser-plugin');
     this.setAttribute('id', 'browser-plugin-' + IdGenerator.GetNextId());
     this.style.width = '100%';
@@ skipping 50 matching lines @@
     internal.handleAttributeMutation(name, oldValue, newValue);
   };
 
   proto.detachedCallback = function() {
     var internal = privates(this).internal;
     if (!internal) {
       return;
     }
     internal.elementAttached = false;
     internal.internalInstanceId = 0;
+    internal.guest.destroy();
     internal.onElementDetached();
   };
 
   // Let the specific view type add extra functionality to its custom element
   // through |proto|.
   if (guestViewContainerType.setupElement) {
     guestViewContainerType.setupElement(proto);
   }
 
   window[guestViewContainerType.VIEW_TYPE] =
       DocumentNatives.RegisterElement(
           guestViewContainerType.VIEW_TYPE.toLowerCase(),
           {prototype: proto});
 
   // Delete the callbacks so developers cannot call them and produce unexpected
   // behavior.
   delete proto.createdCallback;
   delete proto.attachedCallback;
   delete proto.detachedCallback;
   delete proto.attributeChangedCallback;
 }
 
 // Exports.
 exports.GuestViewContainer = GuestViewContainer;