Don't include ComputedStyle.h where not needed.

third_party/WebKit/Source/core/dom/NodeComputedStyle.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2008 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 12 matching lines @@
  */
 
 #ifndef NodeComputedStyle_h
 #define NodeComputedStyle_h
 
 #include "core/dom/LayoutTreeBuilderTraversal.h"
 #include "core/dom/Node.h"
 #include "core/dom/shadow/InsertionPoint.h"
 #include "core/html/HTMLOptGroupElement.h"
 #include "core/layout/LayoutObject.h"
-#include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 inline const ComputedStyle* Node::computedStyle() const {
   return mutableComputedStyle();
 }
 
 inline ComputedStyle* Node::mutableComputedStyle() const {
   if (LayoutObject* layoutObject = this->layoutObject())
     return layoutObject->mutableStyle();
@@ skipping 14 matching lines @@
 }
 
 inline const ComputedStyle& Node::computedStyleRef() const {
   const ComputedStyle* style = computedStyle();
   DCHECK(style);
   return *style;
 }
 
 }  // namespace blink
 #endif  // NodeComputedStyle_h