Have NodeRareData's ensureNodeLists() / ensureMutationObserverData() return a reference

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 9059929553fb2493f72d6f269fb46931d7a9f363..105fe72bb658c9015c8cacca1d5bd4f5598796e7 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -380,7 +380,7 @@ void Node::setNodeValue(const String&)
 
 PassRefPtr<NodeList> Node::childNodes()
 {
-    return ensureRareData().ensureNodeLists()->ensureChildNodeList(this);
+    return ensureRareData().ensureNodeLists().ensureChildNodeList(this);
 }
 
 Node *Node::lastDescendant() const
@@ -1203,8 +1203,8 @@ PassRefPtr<NodeList> Node::getElementsByTagName(const AtomicString& localName)
         return 0;
 
     if (document().isHTMLDocument())
-        return ensureRareData().ensureNodeLists()->addCacheWithAtomicName<HTMLTagNodeList>(this, HTMLTagNodeListType, localName);
-    return ensureRareData().ensureNodeLists()->addCacheWithAtomicName<TagNodeList>(this, TagNodeListType, localName);
+        return ensureRareData().ensureNodeLists().addCacheWithAtomicName<HTMLTagNodeList>(this, HTMLTagNodeListType, localName);
+    return ensureRareData().ensureNodeLists().addCacheWithAtomicName<TagNodeList>(this, TagNodeListType, localName);
 }
 
 PassRefPtr<NodeList> Node::getElementsByTagNameNS(const AtomicString& namespaceURI, const AtomicString& localName)
@@ -1215,23 +1215,23 @@ PassRefPtr<NodeList> Node::getElementsByTagNameNS(const AtomicString& namespaceU
     if (namespaceURI == starAtom)
         return getElementsByTagName(localName);
 
-    return ensureRareData().ensureNodeLists()->addCacheWithQualifiedName(this, namespaceURI.isEmpty() ? nullAtom : namespaceURI, localName);
+    return ensureRareData().ensureNodeLists().addCacheWithQualifiedName(this, namespaceURI.isEmpty() ? nullAtom : namespaceURI, localName);
 }
 
 PassRefPtr<NodeList> Node::getElementsByName(const String& elementName)
 {
-    return ensureRareData().ensureNodeLists()->addCacheWithAtomicName<NameNodeList>(this, NameNodeListType, elementName);
+    return ensureRareData().ensureNodeLists().addCacheWithAtomicName<NameNodeList>(this, NameNodeListType, elementName);
 }
 
 PassRefPtr<NodeList> Node::getElementsByClassName(const String& classNames)
 {
-    return ensureRareData().ensureNodeLists()->addCacheWithName<ClassNodeList>(this, ClassNodeListType, classNames);
+    return ensureRareData().ensureNodeLists().addCacheWithName<ClassNodeList>(this, ClassNodeListType, classNames);
 }
 
 PassRefPtr<RadioNodeList> Node::radioNodeList(const AtomicString& name)
 {
     ASSERT(hasTagName(formTag) || hasTagName(fieldsetTag));
-    return ensureRareData().ensureNodeLists()->addCacheWithAtomicName<RadioNodeList>(this, RadioNodeListType, name);
+    return ensureRareData().ensureNodeLists().addCacheWithAtomicName<RadioNodeList>(this, RadioNodeListType, name);
 }
 
 PassRefPtr<Element> Node::querySelector(const AtomicString& selectors, ExceptionState& es)
@@ -2160,7 +2160,7 @@ void Node::getRegisteredMutationObserversOfType(HashMap<MutationObserver*, Mutat
 void Node::registerMutationObserver(MutationObserver* observer, MutationObserverOptions options, const HashSet<AtomicString>& attributeFilter)
 {
     MutationObserverRegistration* registration = 0;
-    Vector<OwnPtr<MutationObserverRegistration> >& registry = ensureRareData().ensureMutationObserverData()->registry;
+    Vector<OwnPtr<MutationObserverRegistration> >& registry = ensureRareData().ensureMutationObserverData().registry;
     for (size_t i = 0; i < registry.size(); ++i) {
         if (registry[i]->observer() == observer) {
             registration = registry[i].get();
@@ -2197,7 +2197,7 @@ void Node::unregisterMutationObserver(MutationObserverRegistration* registration
 
 void Node::registerTransientMutationObserver(MutationObserverRegistration* registration)
 {
-    ensureRareData().ensureMutationObserverData()->transientRegistry.add(registration);
+    ensureRareData().ensureMutationObserverData().transientRegistry.add(registration);
 }
 
 void Node::unregisterTransientMutationObserver(MutationObserverRegistration* registration)