Oilpan: move Node traversal objects to the heap.

Source/core/dom/NodeIteratorBase.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2000 Frederik Holljen (frederik.holljen@hig.no)
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2004, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef NodeIteratorBase_h
 #define NodeIteratorBase_h
 
+#include "platform/heap/Handle.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 class ExceptionState;
 class Node;
 class NodeFilter;
 
-class NodeIteratorBase {
+class NodeIteratorBase : public WillBeGarbageCollectedMixin {
 public:
+    virtual ~NodeIteratorBase() { }
+
     Node* root() const { return m_root.get(); }
     unsigned whatToShow() const { return m_whatToShow; }
     NodeFilter* filter() const { return m_filter.get(); }
     // |expandEntityReferences| first appeared in "DOM Level 2 Traversal and Range". However, this argument was
     // never implemented, and, in DOM4, the function argument |expandEntityReferences| is removed from
     // Document.createNodeIterator() and Document.createTreeWalker().
     bool expandEntityReferences() const { return false; }
 
+    virtual void trace(Visitor*);
+
 protected:
-    NodeIteratorBase(PassRefPtr<Node>, unsigned whatToShow, PassRefPtr<NodeFilter>);
+    NodeIteratorBase(PassRefPtrWillBeRawPtr<Node>, unsigned whatToShow, PassRefPtrWillBeRawPtr<NodeFilter>);
     short acceptNode(Node*, ExceptionState&) const;
 
 private:
-    RefPtr<Node> m_root;
+    RefPtrWillBeMember<Node> m_root;
     unsigned m_whatToShow;
-    RefPtr<NodeFilter> m_filter;
+    RefPtrWillBeMember<NodeFilter> m_filter;
 };
 
 } // namespace WebCore
 
 #endif // NodeIteratorBase_h