Oilpan: move Node traversal objects to the heap.

Source/core/dom/Document.h

Index: Source/core/dom/Document.h
diff --git a/Source/core/dom/Document.h b/Source/core/dom/Document.h
index ba3991c01785e3cb0400f646c9eb302f30e6591f..35c55046f78da1027a6d408874c54a382989d717 100644
--- a/Source/core/dom/Document.h
+++ b/Source/core/dom/Document.h
@@ -478,13 +478,13 @@ public:
 
     PassRefPtrWillBeRawPtr<Range> createRange();
 
-    PassRefPtr<NodeIterator> createNodeIterator(Node* root, ExceptionState&);
-    PassRefPtr<NodeIterator> createNodeIterator(Node* root, unsigned whatToShow, ExceptionState&);
-    PassRefPtr<NodeIterator> createNodeIterator(Node* root, unsigned whatToShow, PassRefPtr<NodeFilter>, ExceptionState&);
+    PassRefPtrWillBeRawPtr<NodeIterator> createNodeIterator(Node* root, ExceptionState&);
+    PassRefPtrWillBeRawPtr<NodeIterator> createNodeIterator(Node* root, unsigned whatToShow, ExceptionState&);
+    PassRefPtrWillBeRawPtr<NodeIterator> createNodeIterator(Node* root, unsigned whatToShow, PassRefPtrWillBeRawPtr<NodeFilter>, ExceptionState&);
 
-    PassRefPtr<TreeWalker> createTreeWalker(Node* root, ExceptionState&);
-    PassRefPtr<TreeWalker> createTreeWalker(Node* root, unsigned whatToShow, ExceptionState&);
-    PassRefPtr<TreeWalker> createTreeWalker(Node* root, unsigned whatToShow, PassRefPtr<NodeFilter>, ExceptionState&);
+    PassRefPtrWillBeRawPtr<TreeWalker> createTreeWalker(Node* root, ExceptionState&);
+    PassRefPtrWillBeRawPtr<TreeWalker> createTreeWalker(Node* root, unsigned whatToShow, ExceptionState&);
+    PassRefPtrWillBeRawPtr<TreeWalker> createTreeWalker(Node* root, unsigned whatToShow, PassRefPtrWillBeRawPtr<NodeFilter>, ExceptionState&);
 
     // Special support for editing
     PassRefPtrWillBeRawPtr<Text> createEditingTextNode(const String&);
@@ -1241,7 +1241,7 @@ private:
     uint64_t m_domTreeVersion;
     static uint64_t s_globalTreeVersion;
 
-    HashSet<NodeIterator*> m_nodeIterators;
+    WillBeHeapHashSet<RawPtrWillBeWeakMember<NodeIterator> > m_nodeIterators;
     HashSet<Range*> m_ranges;
 
     unsigned short m_listenerTypes;