WIP: Implement CSS transitions on top of InterpolationTypes instead of AnimatableValues

third_party/WebKit/Source/core/animation/css/CSSAnimations.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 105 matching lines @@
 
     struct RunningTransition {
         DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
     public:
         DEFINE_INLINE_TRACE()
         {
             visitor->trace(animation);
         }
 
         Member<Animation> animation;
-        const AnimatableValue* from;
-        const AnimatableValue* to;
+        RefPtr<AnimatableValue> from;
+        RefPtr<AnimatableValue> to;
         RefPtr<AnimatableValue> reversingAdjustedStartValue;
         double reversingShorteningFactor;
     };
 
     HeapVector<Member<RunningAnimation>> m_runningAnimations;
 
     using TransitionMap = HeapHashMap<CSSPropertyID, RunningTransition>;
     TransitionMap m_transitions;
 
     CSSAnimationUpdate m_pendingUpdate;
@@ skipping 53 matching lines @@
 
         Member<Element> m_transitionTarget;
         const CSSPropertyID m_property;
         AnimationEffect::Phase m_previousPhase;
     };
 };
 
 } // namespace blink
 
 #endif