Store IdTargetObserver::m_registry as a reference

Source/core/dom/IdTargetObserverRegistry.h

 /*
  * Copyright (C) 2012 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 19 matching lines @@
 #include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/text/StringHash.h"
 
 namespace WebCore {
 
 class IdTargetObserver;
 
 class IdTargetObserverRegistry {
-    WTF_MAKE_FAST_ALLOCATED;
+    WTF_MAKE_NONCOPYABLE(IdTargetObserverRegistry); WTF_MAKE_FAST_ALLOCATED;
     friend class IdTargetObserver;
 public:
     static PassOwnPtr<IdTargetObserverRegistry> create();
     void notifyObservers(const AtomicString& id);
     bool hasObservers(const AtomicString& id) const;
 
 private:
     IdTargetObserverRegistry() : m_notifyingObserversInSet(0) { }
     void addObserver(const AtomicString& id, IdTargetObserver*);
     void removeObserver(const AtomicString& id, IdTargetObserver*);
     void notifyObserversInternal(const AtomicString& id);
 
     typedef HashSet<IdTargetObserver*> ObserverSet;
     typedef HashMap<StringImpl*, OwnPtr<ObserverSet> > IdToObserverSetMap;
     IdToObserverSetMap m_registry;
     ObserverSet* m_notifyingObserversInSet;
 };
 
 inline void IdTargetObserverRegistry::notifyObservers(const AtomicString& id)
 {
     ASSERT(!m_notifyingObserversInSet);
     if (id.isEmpty() || m_registry.isEmpty())
         return;
     IdTargetObserverRegistry::notifyObserversInternal(id);
 }
 
 } // namespace WebCore
 
 #endif // IdTargetObserverRegistry_h