Clean up forward declarations in Source/core/css

Source/core/css/CSSCalculationValue.h

 /*
  * Copyright (C) 2011, 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 #include "core/css/CSSValue.h"
 #include "core/css/parser/CSSParserValues.h"
 #include "platform/CalculationValue.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class CSSParserValueList;
-class CSSValueList;
 class CalculationValue;
-class CalcExpressionNode;
-class Length;
 
 enum CalcOperator {
     CalcAdd = '+',
     CalcSubtract = '-',
     CalcMultiply = '*',
     CalcDivide = '/'
 };
 
 // The order of this enum should not change since its elements are used as indices
 // in the addSubtractResult matrix.
@@ skipping 86 matching lines @@
     const RefPtrWillBeMember<CSSCalcExpressionNode> m_expression;
     const bool m_nonNegative;
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSCalcValue, isCalcValue());
 
 } // namespace blink
 
 
 #endif // CSSCalculationValue_h