Make IDL Callbacks non-refcounted by default

Source/core/dom/MutationObserver.cpp

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 36 matching lines @@
 
 static unsigned s_observerPriority = 0;
 
 struct MutationObserver::ObserverLessThan {
     bool operator()(const RefPtr<MutationObserver>& lhs, const RefPtr<MutationObserver>& rhs)
     {
         return lhs->m_priority < rhs->m_priority;
     }
 };
 
-PassRefPtr<MutationObserver> MutationObserver::create(PassRefPtr<MutationCallback> callback)
+PassRefPtr<MutationObserver> MutationObserver::create(PassOwnPtr<MutationCallback> callback)
 {
     ASSERT(isMainThread());
     return adoptRef(new MutationObserver(callback));
 }
 
-MutationObserver::MutationObserver(PassRefPtr<MutationCallback> callback)
+MutationObserver::MutationObserver(PassOwnPtr<MutationCallback> callback)
     : m_callback(callback)
     , m_priority(s_observerPriority++)
 {
     ScriptWrappable::init(this);
 }
 
 MutationObserver::~MutationObserver()
 {
     ASSERT(m_registrations.isEmpty());
 }
@@ skipping 183 matching lines @@
                 observers[i]->deliver();
             else
                 suspendedMutationObservers().add(observers[i]);
         }
     }
 
     deliveryInProgress = false;
 }
 
 } // namespace WebCore