Clean up forward declarations in Source/core

Source/core/xml/XSLImportRule.h

 /*
  * This file is part of the XSL implementation.
  *
  * Copyright (C) 2004, 2006, 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 12 matching lines @@
 #ifndef XSLImportRule_h
 #define XSLImportRule_h
 
 #include "core/fetch/ResourcePtr.h"
 #include "core/xml/XSLStyleSheet.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace blink {
 
-class XSLStyleSheetResource;
-
 class XSLImportRule final : public NoBaseWillBeGarbageCollectedFinalized<XSLImportRule> {
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     static PassOwnPtrWillBeRawPtr<XSLImportRule> create(XSLStyleSheet* parentSheet, const String& href)
     {
         ASSERT(RuntimeEnabledFeatures::xsltEnabled());
         return adoptPtrWillBeNoop(new XSLImportRule(parentSheet, href));
     }
 
     virtual ~XSLImportRule();
@@ skipping 15 matching lines @@
 
     RawPtrWillBeMember<XSLStyleSheet> m_parentStyleSheet;
     String m_strHref;
     RefPtrWillBeMember<XSLStyleSheet> m_styleSheet;
     bool m_loading;
 };
 
 } // namespace blink
 
 #endif // XSLImportRule_h