Use alias_for with trivial property aliases

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 53 matching lines @@
 
 using PropertySet = HashSet<CSSPropertyID>;
 
 namespace {
 
 CSSPropertyID propertyForAnimation(CSSPropertyID property)
 {
     switch (property) {
     case CSSPropertyWebkitBackgroundSize:
         return CSSPropertyBackgroundSize;
-    case CSSPropertyWebkitBoxShadow:
-        return CSSPropertyBoxShadow;
     case CSSPropertyWebkitPerspective:
         return CSSPropertyPerspective;
     case CSSPropertyWebkitTransform:
         return CSSPropertyTransform;
-    case CSSPropertyWebkitPerspectiveOrigin:
-        return CSSPropertyPerspectiveOrigin;
-    case CSSPropertyWebkitTransformOrigin:
-        return CSSPropertyTransformOrigin;
     default:
         break;
     }
     return property;
 }
 
 static PassRefPtrWillBeRawPtr<StringKeyframeEffectModel> createKeyframeEffect(StyleResolver* resolver, const Element* animatingElement, Element& element, const ComputedStyle* style, const ComputedStyle* parentStyle, const AtomicString& name, TimingFunction* defaultTimingFunction)
 {
     // When the animating element is null, use its parent for scoping purposes.
     const Element* elementForScoping = animatingElement ? animatingElement : &element;
@@ skipping 746 matching lines @@
     visitor->trace(m_activeInterpolationsForAnimations);
     visitor->trace(m_activeInterpolationsForTransitions);
     visitor->trace(m_newAnimations);
     visitor->trace(m_suppressedAnimationPlayers);
     visitor->trace(m_animationsWithUpdates);
     visitor->trace(m_animationsWithStyleUpdates);
 #endif
 }
 
 } // namespace blink