Implement a module system for the extension bindings JS.

chrome/renderer/resources/extensions/input.ime_custom_bindings.js

Index: chrome/renderer/resources/extensions/input.ime_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/input.ime_custom_bindings.js b/chrome/renderer/resources/extensions/input.ime_custom_bindings.js
index 7e87fbb457be13fc698a0e4e50eb6f3527a1b24f..0d255ba7ca962109836d9de362081cc4d5555958 100644
--- a/chrome/renderer/resources/extensions/input.ime_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/input.ime_custom_bindings.js
@@ -5,9 +5,7 @@
 // Custom bindings for the input ime API. Only injected into the
 // v8 contexts for extensions which have permission for the API.
 
-(function() {
-
-native function GetChromeHidden();
+var GetChromeHidden = natives.GetChromeHidden;
 
 GetChromeHidden().registerCustomHook('input.ime', function() {
   chrome.input.ime.onKeyEvent.dispatch = function(engineID, keyData) {
@@ -36,5 +34,3 @@ GetChromeHidden().registerCustomHook('input.ime', function() {
     }
   };
 });
-
-})();