Remove BisonCSSParser references in comments

Source/core/css/CSSPrimitiveValue.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  *
  * 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 136 matching lines @@
         // This value must come after the last length unit type to enable iteration over the length unit types.
         LengthUnitTypeCount,
     };
 
     typedef Vector<double, CSSPrimitiveValue::LengthUnitTypeCount> CSSLengthArray;
     typedef BitVector CSSLengthTypeArray;
 
     void accumulateLengthArray(CSSLengthArray&, double multiplier = 1) const;
     void accumulateLengthArray(CSSLengthArray&, CSSLengthTypeArray&, double multiplier = 1) const;
 
-    // This enum follows the BisonCSSParser::Units enum augmented with UNIT_FREQUENCY for frequencies.
     enum UnitCategory {
         UNumber,
         UPercent,
         ULength,
         UAngle,
         UTime,
         UFrequency,
         UResolution,
         UOther
     };
@@ skipping 216 matching lines @@
 };
 
 typedef CSSPrimitiveValue::CSSLengthArray CSSLengthArray;
 typedef CSSPrimitiveValue::CSSLengthTypeArray CSSLengthTypeArray;
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSPrimitiveValue, isPrimitiveValue());
 
 } // namespace blink
 
 #endif // CSSPrimitiveValue_h