Revert 157959 "Introduce a new reference graph to SVG*TearOffs."

Source/core/svg/properties/SVGStaticListPropertyTearOff.h

 /*
  * Copyright (C) Research In Motion Limited 2010. 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
@@ skipping 25 matching lines @@
 
     using Base::m_role;
     using Base::m_values;
 
     static PassRefPtr<SVGStaticListPropertyTearOff<PropertyType> > create(SVGElement* contextElement, PropertyType& values)
     {
         ASSERT(contextElement);
         return adoptRef(new SVGStaticListPropertyTearOff<PropertyType>(contextElement, values));
     }
 
-    SVGElement* contextElement() const { return m_contextElement; }
-
     // SVGList API
     void clear(ExceptionState& es)
     {
         Base::clearValues(es);
     }
 
     ListItemType initialize(const ListItemType& newItem, ExceptionState& es)
     {
         return Base::initializeValues(newItem, es);
     }
@@ skipping 31 matching lines @@
     }
 
     virtual bool isReadOnly() const
     {
         return m_role == AnimValRole;
     }
 
     virtual void commitChange()
     {
         ASSERT(m_values);
-        ASSERT(m_contextElement);
-        m_values->commitChange(m_contextElement);
+        m_values->commitChange(m_contextElement.get());
     }
 
     virtual bool processIncomingListItemValue(const ListItemType&, unsigned*)
     {
         // no-op for static lists
         return true;
     }
 
     virtual bool processIncomingListItemWrapper(RefPtr<ListItemTearOff>&, unsigned*)
     {
         ASSERT_NOT_REACHED();
         return true;
     }
 
 private:
-    SVGElement* m_contextElement;
+    RefPtr<SVGElement> m_contextElement;
 };
 
 }
 
 #endif // SVGStaticListPropertyTearOff_h