Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/omnibox_custom_bindings.js

Index: chrome/renderer/resources/extensions/omnibox_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/omnibox_custom_bindings.js b/chrome/renderer/resources/extensions/omnibox_custom_bindings.js
index 13a3c61a2f84b6385977d5ee51a6dedea4d7747e..8e775a8a1c4ca96b7d178a25b3fd83fdb3880b25 100644
--- a/chrome/renderer/resources/extensions/omnibox_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/omnibox_custom_bindings.js
@@ -7,7 +7,7 @@
 
 (function() {
 
-native function GetChromeHidden();
+var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 
 // Remove invalid characters from |text| so that it is suitable to use
 // for |AutocompleteMatch::contents|.
@@ -79,7 +79,7 @@ function parseOmniboxDescription(input) {
   return result;
 }
 
-GetChromeHidden().registerCustomHook('omnibox', function(bindingsAPI) {
+chromeHidden.registerCustomHook('omnibox', function(bindingsAPI) {
   var apiFunctions = bindingsAPI.apiFunctions;
   var sendRequest = bindingsAPI.sendRequest;