Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/input.ime_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 input ime API. Only injected into the
 // v8 contexts for extensions which have permission for the API.
 
-(function() {
+var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
-native function GetChromeHidden();
-
-GetChromeHidden().registerCustomHook('input.ime', function() {
+chromeHidden.registerCustomHook('input.ime', function() {
   chrome.input.ime.onKeyEvent.dispatch = function(engineID, keyData) {
     var args = Array.prototype.slice.call(arguments);
     if (this.validate_) {
       var validationErrors = this.validate_(args);
       if (validationErrors) {
         chrome.input.ime.eventHandled(requestId, false);
         return validationErrors;
       }
     }
     if (this.listeners_.length > 1) {
       console.error('Too many listeners for onKeyEvent: ' + e.stack);
       chrome.input.ime.eventHandled(requestId, false);
       return;
     }
     for (var i = 0; i < this.listeners_.length; i++) {
       try {
         var requestId = keyData.requestId;
         var result = this.listeners_[i].apply(null, args);
         chrome.input.ime.eventHandled(requestId, result);
       } catch (e) {
         console.error('Error in event handler for onKeyEvent: ' + e.stack);
         chrome.input.ime.eventHandled(requestId, false);
       }
     }
   };
 });
-
-})();