Oilpan: move SVG property hierarchy to the heap.

Source/core/svg/SVGURIReference.h

 /*
  * Copyright (C) 2004, 2005, 2008, 2009 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  *
  * 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 SVGURIReference_h
 #define SVGURIReference_h
 
 #include "core/dom/Document.h"
 #include "core/svg/SVGAnimatedString.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Element;
 
-class SVGURIReference {
+class SVGURIReference : public WillBeGarbageCollectedMixin {
 public:
     virtual ~SVGURIReference() { }
 
     bool isKnownAttribute(const QualifiedName&);
     void addSupportedAttributes(HashSet<QualifiedName>&);
 
     static AtomicString fragmentIdentifierFromIRIString(const String&, const TreeScope&);
     static Element* targetElementFromIRIString(const String&, const TreeScope&, AtomicString* = 0, Document* = 0);
 
     static inline bool isExternalURIReference(const String& uri, const Document& document)
     {
         // Fragment-only URIs are always internal
         if (uri.startsWith('#'))
             return false;
 
         // If the URI matches our documents URL, we're dealing with a local reference.
         KURL url = document.completeURL(uri);
         return !equalIgnoringFragmentIdentifier(url, document.url());
     }
 
     const String& hrefString() const { return m_href->currentValue()->value(); }
 
     // JS API
     SVGAnimatedString* href() const { return m_href.get(); }
 
+    virtual void trace(Visitor*);
+
 protected:
     explicit SVGURIReference(SVGElement*);
 
 private:
-    RefPtr<SVGAnimatedString> m_href;
+    RefPtrWillBeMember<SVGAnimatedString> m_href;
 };
 
 } // namespace blink
 
 #endif // SVGURIReference_h