Remove some unused code

Source/core/animation/css/CSSAnimations.cpp

 /*
  * 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 35 matching lines @@
 #include "core/css/CSSValueList.h"
 #include "core/css/resolver/CSSToStyleMap.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Element.h"
 #include "core/dom/PseudoElement.h"
 #include "core/dom/StyleEngine.h"
 #include "core/events/AnimationEvent.h"
 #include "core/events/TransitionEvent.h"
 #include "core/frame/UseCounter.h"
 #include "core/layout/LayoutObject.h"
-#include "core/style/KeyframeList.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 #include "platform/animation/TimingFunction.h"
 #include "public/platform/Platform.h"
 #include "wtf/BitArray.h"
 #include "wtf/HashSet.h"
 
 namespace blink {
 
 using PropertySet = HashSet<CSSPropertyID>;
 
@@ skipping 736 matching lines @@
     visitor->trace(m_activeInterpolationsForAnimations);
     visitor->trace(m_activeInterpolationsForTransitions);
     visitor->trace(m_newAnimations);
     visitor->trace(m_suppressedAnimations);
     visitor->trace(m_animationsWithUpdates);
     visitor->trace(m_animationsWithStyleUpdates);
 #endif
 }
 
 } // namespace blink