Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/experimental.socket_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 bindings for the experimental.socket API.
 
-(function() {
-  native function GetChromeHidden();
-  native function GetNextSocketEventId();
+  var experimentalSocketNatives = requireNative('experimental_socket');
+  var GetNextSocketEventId = experimentalSocketNatives.GetNextSocketEventId;
 
-  var chromeHidden = GetChromeHidden();
+  var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
   chromeHidden.registerCustomHook('experimental.socket', function(api) {
       var apiFunctions = api.apiFunctions;
       var sendRequest = api.sendRequest;
 
       apiFunctions.setHandleRequest('create', function() {
           var args = arguments;
           if (args.length > 3 && args[3] && args[3].onEvent) {
             var id = GetNextSocketEventId();
             args[3].srcId = id;
@@ skipping 27 matching lines @@
               default:
                 console.error('Unexpected SocketEvent, type ' + event.type);
               break;
             }
             if (event.isFinalEvent) {
               delete chromeHidden.socket.handlers[event.srcId];
             }
           }
         });
     });
-
-})();