Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/schema_generated_bindings.js

Index: chrome/renderer/resources/extensions/schema_generated_bindings.js
diff --git a/chrome/renderer/resources/extensions/schema_generated_bindings.js b/chrome/renderer/resources/extensions/schema_generated_bindings.js
index 1a4e8b61744b7423c08726c0a902e627218181b7..381f8cc42e44c9bc33d1db92c896c614512af1ea 100644
--- a/chrome/renderer/resources/extensions/schema_generated_bindings.js
+++ b/chrome/renderer/resources/extensions/schema_generated_bindings.js
@@ -5,15 +5,16 @@
 // This script contains privileged chrome extension related javascript APIs.
 // It is loaded by pages whose URL has the chrome-extension protocol.
 
-var chrome = chrome || {};
 (function() {
-  native function GetChromeHidden();
-  native function GetExtensionAPIDefinition();
-  native function GetNextRequestId();
-  native function StartRequest();
-  native function SetIconCommon();
-
-  var chromeHidden = GetChromeHidden();
+  require('json_schema');
+  require('event_bindings');
+  var natives = requireNative('schema_generated_bindings');
+  var GetExtensionAPIDefinition = natives.GetExtensionAPIDefinition;
+  var GetNextRequestId = natives.GetNextRequestId;
+  var StartRequest = natives.StartRequest;
+  var SetIconCommon = natives.SetIconCommon;
+
+  var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
   // The object to generate the bindings for "internal" APIs in, so that
   // extensions can't directly call them (without access to chromeHidden),