A sizes attribute parser

Source/core/css/CSSPrimitiveValue.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2012 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 593 matching lines @@
     return static_cast<float>(computeLengthDouble(conversionData));
 }
 
 template<> double CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData)
 {
     return computeLengthDouble(conversionData);
 }
 
 double CSSPrimitiveValue::computeLengthDouble(const CSSToLengthConversionData& conversionData)
 {
+    // The logic in this function is duplicated in MediaValues::computeLength
+    // because MediaValues::computeLength needs nearly identical logic, but we haven't found a way to make
+    // CSSPrimitiveValue::computeLengthDouble more generic (to solve both cases) without hurting performance.
     if (m_primitiveUnitType == CSS_CALC)
         return m_value.calc->computeLengthPx(conversionData);
 
     const RenderStyle& style = conversionData.style();
     const RenderStyle* rootStyle = conversionData.rootStyle();
     bool computingFontSize = conversionData.computingFontSize();
 
     double factor;
 
     switch (primitiveType()) {
@@ skipping 797 matching lines @@
     case CSS_SHAPE:
         visitor->trace(m_value.shape);
         break;
     default:
         break;
     }
     CSSValue::traceAfterDispatch(visitor);
 }
 
 } // namespace WebCore