Implement declarative content script API for <webview> [js part].

extensions/renderer/resources/guest_view/web_view_events.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.
 
 // Event management for WebView.
 
 var DeclarativeWebRequestSchema =
     requireNative('schema_registry').GetSchema('declarativeWebRequest');
 var EventBindings = require('event_bindings');
 var IdGenerator = requireNative('id_generator');
@@ skipping 247 matching lines @@
     Object.defineProperty(
         request,
         WebRequestSchema.events[i].name,
         {
           get: webRequestEvent,
           enumerable: true
         }
     );
   }
 
+  request = this.webViewImpl.maybeSetupExperimentalChromeWebViewEvents(request);
   this.webViewImpl.setRequestPropertyOnWebViewElement(request);
 };
 
 WebViewEvents.prototype.getEvents = function() {
   var chromeEvents = this.webViewImpl.maybeGetChromeWebViewEvents();
   for (var eventName in chromeEvents) {
     WEB_VIEW_EVENTS[eventName] = chromeEvents[eventName];
   }
   return WEB_VIEW_EVENTS;
 };
@@ skipping 312 matching lines @@
   }
 };
 
 WebViewEvents.prototype.handleSizeChangedEvent = function(
     event, webViewEvent) {
   this.webViewImpl.onSizeChanged(webViewEvent);
 };
 
 exports.WebViewEvents = WebViewEvents;
 exports.CreateEvent = CreateEvent;