Move rem handling out of CSSParserValues.cpp

Source/core/css/CSSToLengthConversionData.h

 /*
  * Copyright (C) 2013 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 63 matching lines @@
         double m_height;
     };
 
     CSSToLengthConversionData() { }
     CSSToLengthConversionData(const ComputedStyle*, const FontSizes&, const ViewportSize&, float zoom);
     CSSToLengthConversionData(const ComputedStyle* currStyle, const ComputedStyle* rootStyle, const LayoutView*, float zoom);
 
     float zoom() const { return m_zoom; }
 
     float emFontSize() const { return m_fontSizes.em(); }
-    float remFontSize() const { return m_fontSizes.rem(); }
+    float remFontSize() const;
     float exFontSize() const { return m_fontSizes.ex(); }
     float chFontSize() const { return m_fontSizes.ch(); }
 
     // Accessing these marks the style as having viewport units
     double viewportWidthPercent() const;
     double viewportHeightPercent() const;
     double viewportMinPercent() const;
     double viewportMaxPercent() const;
 
     void setFontSizes(const FontSizes& fontSizes) { m_fontSizes = fontSizes; }
@@ skipping 11 matching lines @@
 private:
     const ComputedStyle* m_style;
     FontSizes m_fontSizes;
     ViewportSize m_viewportSize;
     float m_zoom;
 };
 
 } // namespace blink
 
 #endif