Add support for AMD to the extensions module system.

gin/modules/module_registry.h

Index: gin/modules/module_registry.h
diff --git a/gin/modules/module_registry.h b/gin/modules/module_registry.h
index 5775a34a3db21ee563921fe55111bf721ec3f6bf..6b1449151da796612f88f89836a175a48d2afdbf 100644
--- a/gin/modules/module_registry.h
+++ b/gin/modules/module_registry.h
@@ -75,6 +75,8 @@ class GIN_EXPORT ModuleRegistry {
     return unsatisfied_dependencies_;
   }
 
+  v8::Handle<v8::Value> GetModule(v8::Isolate* isolate, const std::string& id);
+
  private:
   typedef ScopedVector<PendingModule> PendingModuleVector;
   typedef std::map<std::string, LoadModuleCallback> LoadModuleCallbackMap;
@@ -89,8 +91,6 @@ class GIN_EXPORT ModuleRegistry {
   bool CheckDependencies(PendingModule* pending);
   bool AttemptToLoad(v8::Isolate* isolate, scoped_ptr<PendingModule> pending);
 
-  v8::Handle<v8::Value> GetModule(v8::Isolate* isolate, const std::string& id);
-
   std::set<std::string> available_modules_;
   std::set<std::string> unsatisfied_dependencies_;