Use StringKeyframes to make CSS Animations responsive to style changes

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 86 matching lines @@
     {
         ensureKeyframeGroups();
         return m_hasSyntheticKeyframes;
     }
 
     DECLARE_VIRTUAL_TRACE();
 
     // 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 AnimatableValues are obsolete.
     void forceConversionsToAnimatableValues(Element&, const LayoutStyle* baseStyle);
-    void updateNeutralKeyframeAnimatableValues(CSSPropertyID, PassRefPtrWillBeRawPtr<AnimatableValue>);
+    bool updateNeutralKeyframeAnimatableValues(CSSPropertyID, PassRefPtrWillBeRawPtr<AnimatableValue>);
 
     template<typename T>
     inline void forEachInterpolation(const T& callback) { m_interpolationEffect->forEachInterpolation(callback); }
 
     static KeyframeVector normalizedKeyframesForInspector(const KeyframeVector& keyframes) { return normalizedKeyframes(keyframes); }
 
     bool affects(CSSPropertyID property) const override
     {
         ensureKeyframeGroups();
         return m_keyframeGroups->contains(property);
@@ skipping 83 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