Adds ModuleRegistryObserver interface

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 2270d31ab38ec8387477c7f970943e5fe11f0e0d..5775a34a3db21ee563921fe55111bf721ec3f6bf 100644
--- a/gin/modules/module_registry.h
+++ b/gin/modules/module_registry.h
@@ -14,11 +14,13 @@
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
+#include "base/observer_list.h"
 #include "gin/gin_export.h"
 #include "v8/include/v8.h"
 
 namespace gin {
 
+class ModuleRegistryObserver;
 struct PendingModule;
 
 // This class implements the Asynchronous Module Definition (AMD) API.
@@ -43,6 +45,13 @@ class GIN_EXPORT ModuleRegistry {
   static void RegisterGlobals(v8::Isolate* isolate,
                               v8::Handle<v8::ObjectTemplate> templ);
 
+  // Installs the necessary functions needed for modules.
+  // WARNING: this may execute script in the page.
+  static void InstallGlobals(v8::Isolate* isolate, v8::Handle<v8::Object> obj);
+
+  void AddObserver(ModuleRegistryObserver* observer);
+  void RemoveObserver(ModuleRegistryObserver* observer);
+
   // The caller must have already entered our context.
   void AddBuiltinModule(v8::Isolate* isolate, const std::string& id,
                         v8::Handle<v8::Value> module);
@@ -90,6 +99,8 @@ class GIN_EXPORT ModuleRegistry {
   PendingModuleVector pending_modules_;
   v8::Persistent<v8::Object> modules_;
 
+  ObserverList<ModuleRegistryObserver> observer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(ModuleRegistry);
 };