Gin: Allow multiple callers to wait for the same module in ModuleRegistry.

gin/modules/module_registry.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GIN_MODULES_MODULE_REGISTRY_H_
 #define GIN_MODULES_MODULE_REGISTRY_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 59 matching lines @@
   const std::set<std::string>& available_modules() const {
     return available_modules_;
   }
 
   const std::set<std::string>& unsatisfied_dependencies() const {
     return unsatisfied_dependencies_;
   }
 
  private:
   typedef ScopedVector<PendingModule> PendingModuleVector;
-  typedef std::map<std::string, LoadModuleCallback> LoadModuleCallbackMap;
+  typedef std::multimap<std::string, LoadModuleCallback> LoadModuleCallbackMap;
 
   explicit ModuleRegistry(v8::Isolate* isolate);
 
   void Load(v8::Isolate* isolate, scoped_ptr<PendingModule> pending);
   void RegisterModule(v8::Isolate* isolate,
                       const std::string& id,
                       v8::Handle<v8::Value> module);
 
   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_;
 
   LoadModuleCallbackMap waiting_callbacks_;
 
   PendingModuleVector pending_modules_;
   v8::Persistent<v8::Object> modules_;
 
   ObserverList<ModuleRegistryObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(ModuleRegistry);
 };
 
 }  // namespace gin
 
 #endif  // GIN_MODULES_MODULE_REGISTRY_H_