Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/miscellaneous_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.
 
 // This script contains unprivileged javascript APIs related to chrome
 // extensions.  It is loaded by any extension-related context, such as content
 // scripts or background pages.
 // See user_script_slave.cc for script that is loaded by content scripts only.
 // TODO(mpcomplete): we also load this in regular web pages, but don't need to.
 
-var chrome = chrome || {};
-(function () {
-  native function OpenChannelToExtension(sourceId, targetId, name);
-  native function CloseChannel(portId, notifyBrowser);
-  native function PortAddRef(portId);
-  native function PortRelease(portId);
-  native function PostMessage(portId, msg);
-  native function GetChromeHidden();
-  native function GetL10nMessage();
-  native function Print();
+  var OpenChannelToExtension = natives.OpenChannelToExtension;
+  var CloseChannel = natives.CloseChannel;
+  var PortAddRef = natives.PortAddRef;
+  var PortRelease = natives.PortRelease;
+  var PostMessage = natives.PostMessage;
+  var GetChromeHidden = natives.GetChromeHidden;
+  var GetL10nMessage = natives.GetL10nMessage;
+  var Print = natives.Print;
 
   var chromeHidden = GetChromeHidden();
   var manifestVersion;
 
   // The reserved channel name for the sendRequest API.
   chromeHidden.kRequestChannel = "chrome.extension.sendRequest";
 
   // Map of port IDs to port object.
   var ports = {};
 
@@ skipping 251 matching lines @@
       if (!path.length || path[0] != "/")
         path = "/" + path;
       return "chrome-extension://" + extensionId + path;
     };
 
     chrome.i18n = chrome.i18n || {};
     chrome.i18n.getMessage = function(message_name, placeholders) {
       return GetL10nMessage(message_name, placeholders, extensionId);
     };
   });
-
-})();