<webview>: Context menu API implementation CL.

chrome/renderer/resources/extensions/webview_custom_bindings.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.
 
 // Custom binding for <webview> contextMenus API.
 // Note that this file mimics custom bindings for chrome.contextMenus API
 // which resides in context_menus_custom_bindings.js. The functions in this file
 // have an extra instanceId parameter in the beginning, which corresponds to the
 // id of the <webview>.
 //
@@ skipping 38 matching lines @@
   webviewContextMenus.ensureListenerSetup = function() {
     if (webviewContextMenus.listening) {
       return;
     }
     webviewContextMenus.listening = true;
     webviewContextMenus.event.addListener(function() {
       // An extension context menu item has been clicked on - fire the onclick
       // if there is one.
       var id = arguments[0].menuItemId;
       var instanceId = arguments[0].webviewInstanceId;
+      delete arguments[0].webviewInstanceId;
       var onclick = webviewContextMenus.handlersForId(instanceId, id)[id];
       if (onclick) {
         $Function.apply(onclick, null, arguments);
       }
     });
   };
 
   apiFunctions.setHandleRequest('contextMenusCreate', function() {
     var args = arguments;
     var id = contextMenuNatives.GetNextContextMenuId();
@@ skipping 51 matching lines @@
       return;
     }
     var instanceId = request.args[0];
     webviewContextMenus.stringIdHandlers[instanceId] = {};
     webviewContextMenus.generatedIdHandlers[instanceId] = {};
   });
 
 });
 
 exports.WebView = binding.generate();