Clean up forward declarations in Source/core/html

Source/core/html/HTMLLinkElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Google 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 20 matching lines @@
 #include "core/fetch/StyleSheetResource.h"
 #include "core/fetch/StyleSheetResourceClient.h"
 #include "core/html/HTMLElement.h"
 #include "core/html/LinkRelAttribute.h"
 #include "core/html/LinkResource.h"
 #include "core/loader/LinkLoader.h"
 #include "core/loader/LinkLoaderClient.h"
 
 namespace blink {
 
-class DocumentFragment;
 class HTMLLinkElement;
 class KURL;
 class LinkImport;
 
 template<typename T> class EventSender;
 typedef EventSender<HTMLLinkElement> LinkEventSender;
 
 //
 // LinkStyle handles dynaically change-able link resources, which is
 // typically @rel="stylesheet".
@@ skipping 157 matching lines @@
     Vector<IntSize> m_iconSizes;
     LinkRelAttribute m_relAttribute;
 
     bool m_createdByParser;
     bool m_isInShadowTree;
 };
 
 } // namespace blink
 
 #endif // HTMLLinkElement_h