Remove 'writable:false' from webview.request's definition since false is

chrome/renderer/resources/extensions/web_view.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.
 
 // This module implements Webview (<webview>) as a custom element that wraps a
 // BrowserPlugin object element. The object element is hidden within
 // the shadow DOM of the Webview element.
 
 var DocumentNatives = requireNative('document_natives');
 var EventBindings = require('event_bindings');
@@ skipping 878 matching lines @@
     );
     this.maybeAttachWebRequestEventToObject(this.webviewNode,
                                             WebRequestSchema.events[i].name,
                                             webRequestEvent);
   }
   Object.defineProperty(
       this.webviewNode,
       'request',
       {
         value: request,
-        enumerable: true,
-        writable: false
+        enumerable: true
       }
   );
 };
 
 /** @private */
 WebViewInternal.prototype.getUserAgent = function() {
   return this.userAgentOverride || navigator.userAgent;
 };
 
 /** @private */
@@ skipping 165 matching lines @@
 
 /**
  * Implemented when the experimental API is available.
  * @private
  */
 WebViewInternal.prototype.setupExperimentalContextMenus_ = function() {};
 
 exports.WebView = WebView;
 exports.WebViewInternal = WebViewInternal;
 exports.CreateEvent = CreateEvent;