[SVG] SVGLength{,List} migration to new SVG property impl.

Source/core/animation/AnimatableSVGLength.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 18 matching lines @@
  */
 
 #ifndef AnimatableSVGLength_h
 #define AnimatableSVGLength_h
 
 #include "core/animation/AnimatableValue.h"
 #include "core/svg/SVGLength.h"
 
 namespace WebCore {
 
-class AnimatableSVGLength: public AnimatableValue {
+class AnimatableSVGLength : public AnimatableValue {
 public:
     virtual ~AnimatableSVGLength() { }
 
-    static PassRefPtr<AnimatableSVGLength> create(const SVGLength& length)
+    static PassRefPtr<AnimatableSVGLength> create(PassRefPtr<SVGLength> length)
     {
         return adoptRef(new AnimatableSVGLength(length));
     }
 
-    const SVGLength& toSVGLength() const
+    SVGLength* toSVGLength() const
     {
-        return m_length;
+        return m_length.get();
     }
 
 protected:
     virtual PassRefPtr<AnimatableValue> interpolateTo(const AnimatableValue*, double fraction) const OVERRIDE;
     virtual PassRefPtr<AnimatableValue> addWith(const AnimatableValue*) const OVERRIDE;
 
 private:
-    AnimatableSVGLength(const SVGLength& length)
+    AnimatableSVGLength(PassRefPtr<SVGLength> length)
         : m_length(length)
     {
     }
 
     virtual AnimatableType type() const { return TypeSVGLength; }
     virtual bool equalTo(const AnimatableValue*) const OVERRIDE;
 
-    SVGLength m_length;
+    RefPtr<SVGLength> m_length;
 };
 
 DEFINE_ANIMATABLE_VALUE_TYPE_CASTS(AnimatableSVGLength, isSVGLength());
 
 } // namespace WebCore
 
 #endif // AnimatableSVGLength_h