Have ChildFrameDisconnector / ChildListMutationScope deal with references

Source/core/dom/MutationObserverInterestGroup.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 20 matching lines @@
 #include "config.h"
 
 #include "core/dom/MutationObserverInterestGroup.h"
 
 #include "core/dom/MutationRecord.h"
 #include "core/dom/Node.h"
 #include "core/dom/QualifiedName.h"
 
 namespace WebCore {
 
-PassOwnPtr<MutationObserverInterestGroup> MutationObserverInterestGroup::createIfNeeded(Node* target, MutationObserver::MutationType type, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName)
+PassOwnPtr<MutationObserverInterestGroup> MutationObserverInterestGroup::createIfNeeded(Node& target, MutationObserver::MutationType type, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName)
 {
     ASSERT((type == MutationObserver::Attributes && attributeName) || !attributeName);
     HashMap<MutationObserver*, MutationRecordDeliveryOptions> observers;
-    target->getRegisteredMutationObserversOfType(observers, type, attributeName);
+    target.getRegisteredMutationObserversOfType(observers, type, attributeName);
     if (observers.isEmpty())
         return nullptr;
 
     return adoptPtr(new MutationObserverInterestGroup(observers, oldValueFlag));
 }
 
 MutationObserverInterestGroup::MutationObserverInterestGroup(HashMap<MutationObserver*, MutationRecordDeliveryOptions>& observers, MutationRecordDeliveryOptions oldValueFlag)
     : m_oldValueFlag(oldValueFlag)
 {
     ASSERT(!observers.isEmpty());
@@ skipping 23 matching lines @@
             if (mutation->oldValue().isNull())
                 mutationWithNullOldValue = mutation;
             else
                 mutationWithNullOldValue = MutationRecord::createWithNullOldValue(mutation).get();
         }
         observer->enqueueMutationRecord(mutationWithNullOldValue);
     }
 }
 
 } // namespace WebCore