Implement animation tainted custom property values

third_party/WebKit/Source/core/css/PropertySetCSSStyleDeclaration.h

 /*
  * Copyright (C) 2012 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 61 matching lines @@
                            bool important,
                            ExceptionState&) final;
 
   bool cssPropertyMatches(CSSPropertyID, const CSSValue*) const final;
 
  protected:
   enum MutationType { NoChanges, PropertyChanged };
   virtual void willMutate() {}
   virtual void didMutate(MutationType) {}
   virtual MutableStylePropertySet& propertySet() const = 0;
+  virtual bool isKeyframeStyle() const { return false; }
 };
 
 class PropertySetCSSStyleDeclaration
     : public AbstractPropertySetCSSStyleDeclaration {
  public:
   PropertySetCSSStyleDeclaration(MutableStylePropertySet& propertySet)
       : m_propertySet(&propertySet) {}
 
   DECLARE_VIRTUAL_TRACE();
 
@@ skipping 46 matching lines @@
   Element* parentElement() const override { return m_parentElement; }
 
   void didMutate(MutationType) override;
 
   Member<Element> m_parentElement;
 };
 
 }  // namespace blink
 
 #endif