blink: Cleanup core class forward declarations

third_party/WebKit/Source/core/animation/DocumentAnimations.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 18 matching lines @@
  */
 
 #ifndef DocumentAnimations_h
 #define DocumentAnimations_h
 
 #include "core/CSSPropertyNames.h"
 
 namespace blink {
 
 class Document;
-class Node;
 
 class DocumentAnimations {
  public:
   static void updateAnimationTimingForAnimationFrame(Document&);
   static bool needsAnimationTimingUpdate(const Document&);
   static void updateAnimationTimingIfNeeded(Document&);
 
   // Updates existing animations as part of generating a new (document
   // lifecycle) frame.
   static void updateAnimations(Document&);
 
  private:
   DocumentAnimations() {}
 };
 
 }  // namespace blink
 
 #endif