Move some extensions renderer resources to extensions_renderer_resources.grd.

extensions/renderer/resources/context_menus_custom_bindings.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.
 
 // Custom binding for the contextMenus API.
 
 var binding = require('binding').Binding.create('contextMenus');
 
 var contextMenuNatives = requireNative('context_menus');
 var sendRequest = require('sendRequest').sendRequest;
@@ skipping 81 matching lines @@
                                  function(name, request, response) {
     if (chrome.runtime.lastError) {
       return;
     }
     contextMenus.generatedIdHandlers = {};
     contextMenus.stringIdHandlers = {};
   });
 });
 
 exports.binding = binding.generate();