[Oilpan] Migrate most classes under core/animations to Oilpan heap.

Source/core/animation/DefaultSVGInterpolation.h

 // Copyright 2015 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 DefaultSVGInterpolation_h
 #define DefaultSVGInterpolation_h
 
 #include "core/animation/SVGInterpolation.h"
 
 namespace blink {
 
 class DefaultSVGInterpolation : public SVGInterpolation {
 public:
-    static PassRefPtrWillBeRawPtr<DefaultSVGInterpolation> create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
+    static DefaultSVGInterpolation* create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
     {
-        return adoptRefWillBeNoop(new DefaultSVGInterpolation(start, end, attribute));
+        return new DefaultSVGInterpolation(start, end, attribute);
     }
 
     virtual PassRefPtrWillBeRawPtr<SVGPropertyBase> interpolatedValue(SVGElement&) const override final;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     DefaultSVGInterpolation(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute);
 
     RefPtrWillBeMember<SVGPropertyBase> m_start;
     RefPtrWillBeMember<SVGPropertyBase> m_end;
 };
 
 }
 
 #endif // DefaultSVGInterpolation_h