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 f77ebd605b47ace59bdfd91b802e499ff3f12e01..4aa81909172aa5946aa67977e085ccb7ae6e08f6 100644
--- a/chrome/renderer/resources/extensions/omnibox_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/omnibox_custom_bindings.js
@@ -5,9 +5,7 @@
 // Custom bindings for the omnibox API. Only injected into the v8 contexts
 // for extensions which have permission for the omnibox API.
 
-(function() {
-
-native function GetChromeHidden();
+var GetChromeHidden = natives.GetChromeHidden;
 
 // Remove invalid characters from |text| so that it is suitable to use
 // for |AutocompleteMatch::contents|.
@@ -109,5 +107,3 @@ GetChromeHidden().registerCustomHook('omnibox', function(bindingsAPI) {
     chrome.Event.prototype.dispatch.apply(this, [text, suggestCallback]);
   };
 });
-
-})();