Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/web_request_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 webRequest API.
 
-(function() {
+var webRequestNatives = requireNative('web_request');
+var GetUniqueSubEventName = webRequestNatives.GetUniqueSubEventName;
 
-native function GetChromeHidden();
-native function GetUniqueSubEventName(eventName);
-
-var chromeHidden = GetChromeHidden();
+var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
 // WebRequestEvent object. This is used for special webRequest events with
 // extra parameters. Each invocation of addListener creates a new named
 // sub-event. That sub-event is associated with the extra parameters in the
 // browser process, so that only it is dispatched when the main event occurs
 // matching the extra parameters.
 //
 // Example:
 //   chrome.webRequest.onBeforeRequest.addListener(
 //       callback, {urls: 'http://*.google.com/*'});
@@ skipping 142 matching lines @@
     sendRequest(this.name, args, this.definition.parameters,
                 {forIOThread: true});
   });
 
   apiFunctions.setHandleRequest('handlerBehaviorChanged', function() {
     var args = Array.prototype.slice.call(arguments);
     sendRequest(this.name, args, this.definition.parameters,
                 {forIOThread: true});
   });
 });
-
-})();