Clean up forward declarations in Source/core/css

Source/core/css/CSSImageGeneratorValue.h

 /*
  * Copyright (C) 2008 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 18 matching lines @@
 #include "core/css/CSSValue.h"
 #include "platform/geometry/IntSizeHash.h"
 #include "wtf/HashCountedSet.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class ResourceFetcher;
 class Image;
 class RenderObject;
-class StyleResolver;
 
 struct SizeAndCount {
     SizeAndCount(IntSize newSize = IntSize(), int newCount = 0)
         : size(newSize)
         , count(newCount)
     {
     }
 
     IntSize size;
     int count;
@@ skipping 37 matching lines @@
     GC_PLUGIN_IGNORE("366546")
     OwnPtr<Persistent<CSSImageGeneratorValue> > m_keepAlive;
 #endif
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSImageGeneratorValue, isImageGeneratorValue());
 
 } // namespace blink
 
 #endif // CSSImageGeneratorValue_h