Clean up forward declarations in Source/core/css

Source/core/css/CSSLineBoxContainValue.h

 /*
  * Copyright (C) 2011 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 13 matching lines @@
  */
 
 #ifndef CSSLineBoxContainValue_h
 #define CSSLineBoxContainValue_h
 
 #include "core/css/CSSValue.h"
 #include "wtf/PassRefPtr.h"
 
 namespace blink {
 
-class CSSPrimitiveValue;
-
 enum LineBoxContainFlags { LineBoxContainNone = 0x0, LineBoxContainBlock = 0x1, LineBoxContainInline = 0x2, LineBoxContainFont = 0x4, LineBoxContainGlyphs = 0x8,
                            LineBoxContainReplaced = 0x10, LineBoxContainInlineBox = 0x20 };
 typedef unsigned LineBoxContain;
 
 // Used for text-CSSLineBoxContain and box-CSSLineBoxContain
 class CSSLineBoxContainValue : public CSSValue {
 public:
     static PassRefPtrWillBeRawPtr<CSSLineBoxContainValue> create(LineBoxContain value)
     {
         return adoptRefWillBeNoop(new CSSLineBoxContainValue(value));
@@ skipping 10 matching lines @@
 
 private:
     explicit CSSLineBoxContainValue(LineBoxContain);
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSLineBoxContainValue, isLineBoxContainValue());
 
 } // namespace
 
 #endif