Have MutationObserverRegistration deal with references instead of pointers

Source/core/dom/MutationObserverRegistration.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 19 matching lines @@
 
 #include "config.h"
 
 #include "core/dom/MutationObserverRegistration.h"
 
 #include "core/dom/Node.h"
 #include "core/dom/QualifiedName.h"
 
 namespace WebCore {
 
-PassOwnPtr<MutationObserverRegistration> MutationObserverRegistration::create(PassRefPtr<MutationObserver> observer, Node* registrationNode, MutationObserverOptions options, const HashSet<AtomicString>& attributeFilter)
+PassOwnPtr<MutationObserverRegistration> MutationObserverRegistration::create(MutationObserver& observer, Node& registrationNode, MutationObserverOptions options, const HashSet<AtomicString>& attributeFilter)
 {
     return adoptPtr(new MutationObserverRegistration(observer, registrationNode, options, attributeFilter));
 }
 
-MutationObserverRegistration::MutationObserverRegistration(PassRefPtr<MutationObserver> observer, Node* registrationNode, MutationObserverOptions options, const HashSet<AtomicString>& attributeFilter)
+MutationObserverRegistration::MutationObserverRegistration(MutationObserver& observer, Node& registrationNode, MutationObserverOptions options, const HashSet<AtomicString>& attributeFilter)
     : m_observer(observer)
     , m_registrationNode(registrationNode)
     , m_options(options)
     , m_attributeFilter(attributeFilter)
 {
     m_observer->observationStarted(this);
 }
 
 MutationObserverRegistration::~MutationObserverRegistration()
 {
     clearTransientRegistrations();
     m_observer->observationEnded(this);
 }
 
 void MutationObserverRegistration::resetObservation(MutationObserverOptions options, const HashSet<AtomicString>& attributeFilter)
 {
     clearTransientRegistrations();
     m_options = options;
     m_attributeFilter = attributeFilter;
 }
 
-void MutationObserverRegistration::observedSubtreeNodeWillDetach(Node* node)
+void MutationObserverRegistration::observedSubtreeNodeWillDetach(Node& node)
 {
     if (!isSubtree())
         return;
 
-    node->registerTransientMutationObserver(this);
+    node.registerTransientMutationObserver(this);
     m_observer->setHasTransientRegistration();
 
     if (!m_transientRegistrationNodes) {
         m_transientRegistrationNodes = adoptPtr(new NodeHashSet);
 
         ASSERT(!m_registrationNodeKeepAlive);
-        m_registrationNodeKeepAlive = m_registrationNode; // Balanced in clearTransientRegistrations.
+        m_registrationNodeKeepAlive = PassRefPtr<Node>(m_registrationNode); // Balanced in clearTransientRegistrations.
     }
-    m_transientRegistrationNodes->add(node);
+    m_transientRegistrationNodes->add(&node);
 }
 
 void MutationObserverRegistration::clearTransientRegistrations()
 {
     if (!m_transientRegistrationNodes) {
         ASSERT(!m_registrationNodeKeepAlive);
         return;
     }
 
     for (NodeHashSet::iterator iter = m_transientRegistrationNodes->begin(); iter != m_transientRegistrationNodes->end(); ++iter)
         (*iter)->unregisterTransientMutationObserver(this);
 
     m_transientRegistrationNodes.clear();
 
     ASSERT(m_registrationNodeKeepAlive);
     m_registrationNodeKeepAlive = nullptr; // Balanced in observeSubtreeNodeWillDetach.
 }
 
 void MutationObserverRegistration::unregister()
 {
-    m_registrationNode->unregisterMutationObserver(this);
+    m_registrationNode.unregisterMutationObserver(this);
     // The above line will cause this object to be deleted, so don't do any more in this function.
 }
 
-bool MutationObserverRegistration::shouldReceiveMutationFrom(Node* node, MutationObserver::MutationType type, const QualifiedName* attributeName) const
+bool MutationObserverRegistration::shouldReceiveMutationFrom(Node& node, MutationObserver::MutationType type, const QualifiedName* attributeName) const
 {
     ASSERT((type == MutationObserver::Attributes && attributeName) || !attributeName);
     if (!(m_options & type))
         return false;
 
     if (m_registrationNode != node && !isSubtree())
         return false;
 
     if (type != MutationObserver::Attributes || !(m_options & MutationObserver::AttributeFilter))
         return true;
 
     if (!attributeName->namespaceURI().isNull())
         return false;
 
     return m_attributeFilter.contains(attributeName->localName());
 }
 
 void MutationObserverRegistration::addRegistrationNodesToSet(HashSet<Node*>& nodes) const
 {
-    nodes.add(m_registrationNode);
+    nodes.add(&m_registrationNode);
     if (!m_transientRegistrationNodes)
         return;
     for (NodeHashSet::const_iterator iter = m_transientRegistrationNodes->begin(); iter != m_transientRegistrationNodes->end(); ++iter)
         nodes.add(iter->get());
 }
 
 } // namespace WebCore