Oilpan: move SVG property hierarchy to the heap.

Source/core/svg/properties/SVGPropertyHelper.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SVGPropertyHelper_h
 #define SVGPropertyHelper_h
 
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/svg/properties/SVGProperty.h"
 
 namespace blink {
 
 template<typename Derived>
 class SVGPropertyHelper : public SVGPropertyBase {
 public:
     SVGPropertyHelper()
         : SVGPropertyBase(Derived::classType())
     {
     }
 
-    virtual PassRefPtr<SVGPropertyBase> cloneForAnimation(const String& value) const
+    virtual PassRefPtrWillBeRawPtr<SVGPropertyBase> cloneForAnimation(const String& value) const
     {
-        RefPtr<Derived> property = Derived::create();
+        RefPtrWillBeRawPtr<Derived> property = Derived::create();
         property->setValueAsString(value, IGNORE_EXCEPTION);
         return property.release();
     }
 };
 
-}
+} // namespace blink
 
 #endif // SVGPropertyHelper_h