Update a result vector when sampling animation effects.

Source/core/animation/KeyframeEffectModel.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 68 matching lines @@
     const KeyframeVector& getFrames() const { return m_keyframes; }
     // FIXME: Implement setFrames()
 
     const PropertySpecificKeyframeVector& getPropertySpecificKeyframes(CSSPropertyID id) const
     {
         ensureKeyframeGroups();
         return m_keyframeGroups->get(id)->keyframes();
     }
 
     // AnimationEffect implementation.
-    virtual PassOwnPtrWillBeRawPtr<WillBeHeapVector<RefPtrWillBeMember<Interpolation>>> sample(int iteration, double fraction, double iterationDuration) const override;
+    virtual void sample(int iteration, double fraction, double iterationDuration, OwnPtrWillBeRawPtr<WillBeHeapVector<RefPtrWillBeMember<Interpolation>>>&) const override;
 
     virtual bool isKeyframeEffectModel() const override { return true; }
 
     virtual bool isAnimatableValueKeyframeEffectModel() const { return false; }
     virtual bool isStringKeyframeEffectModel() const { return false; }
 
     virtual void trace(Visitor*) override;
 
     // FIXME: This is a hack used to resolve CSSValues to AnimatableValues while we have a valid handle on an element.
     // This should be removed once StringKeyframes no longer uses InterpolableAnimatableValues.
@@ skipping 72 matching lines @@
 
 template <>
 inline bool KeyframeEffectModel<AnimatableValueKeyframe>::isAnimatableValueKeyframeEffectModel() const { return true; }
 
 template <>
 inline bool KeyframeEffectModel<StringKeyframe>::isStringKeyframeEffectModel() const { return true; }
 
 } // namespace blink
 
 #endif // KeyframeEffectModel_h