Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/event.js

Index: chrome/renderer/resources/extensions/event.js
diff --git a/chrome/renderer/resources/extensions/event.js b/chrome/renderer/resources/extensions/event.js
index 2cf78a8665a015092f4d457aef5d9c3ce067404c..a8f7d33536980fee6fa8ad8ac8e6d359d26b121d 100644
--- a/chrome/renderer/resources/extensions/event.js
+++ b/chrome/renderer/resources/extensions/event.js
@@ -2,14 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-var chrome = chrome || {};
 (function () {
-  native function GetChromeHidden();
-  native function AttachEvent(eventName);
-  native function DetachEvent(eventName, manual);
-  native function Print();
+  var eventBindingsNatives = requireNative('event_bindings');
+  var AttachEvent = eventBindingsNatives.AttachEvent;
+  var DetachEvent = eventBindingsNatives.DetachEvent;
+  var Print = eventBindingsNatives.Print;
 
-  var chromeHidden = GetChromeHidden();
+  var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
   // Local implementation of JSON.parse & JSON.stringify that protect us
   // from being clobbered by an extension.