Moved the contextmenu webview API to stable, and removed the experimental API infrastructure.

extensions/renderer/resources/guest_view/web_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 CreateEvent = require('guestViewEvents').CreateEvent;
 var DeclarativeWebRequestSchema =
     requireNative('schema_registry').GetSchema('declarativeWebRequest');
 var EventBindings = require('event_bindings');
 var GuestViewEvents = require('guestViewEvents').GuestViewEvents;
 var IdGenerator = requireNative('id_generator');
 var WebRequestEvent = require('webRequestInternal').WebRequestEvent;
 var WebRequestSchema =
     requireNative('schema_registry').GetSchema('webRequest');
 var WebViewActionRequests =
     require('webViewActionRequests').WebViewActionRequests;
 
 var WebRequestMessageEvent = CreateEvent('webViewInternal.onMessage');
 
 function WebViewEvents(webViewImpl) {
   GuestViewEvents.call(this, webViewImpl);
 
   this.setupWebRequestEvents();
-  this.view.setupExperimentalContextMenus();
+  this.view.maybeSetupContextMenus();
 }
 
 WebViewEvents.prototype.__proto__ = GuestViewEvents.prototype;
 
 // A dictionary of <webview> extension events to be listened for. This
 // dictionary augments |GuestViewEvents.EVENTS| in guest_view_events.js. See the
 // documentation there for details.
 WebViewEvents.EVENTS = {
   'close': {
     evt: CreateEvent('webViewInternal.onClose')
@@ skipping 236 matching lines @@
   WebRequestMessageEvent.addListener(function() {
     // Re-dispatch to subEvent's listeners.
     $Function.apply(this.dispatch, this, $Array.slice(arguments));
   }.bind(this), {instanceId: opt_webViewInstanceId || 0});
 }
 
 DeclarativeWebRequestEvent.prototype.__proto__ = EventBindings.Event.prototype;
 
 // Exports.
 exports.WebViewEvents = WebViewEvents;