Calculate Underline thickness from Font

Source/platform/fonts/FontMetrics.h

 /*
  * Copyright (C) Research In Motion Limited 2010-2011. 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 19 matching lines @@
 class FontMetrics {
 public:
     FontMetrics()
         : m_unitsPerEm(gDefaultUnitsPerEm)
         , m_ascent(0)
         , m_descent(0)
         , m_lineGap(0)
         , m_lineSpacing(0)
         , m_xHeight(0)
         , m_zeroWidth(0)
+        , m_underlinethickness(0)
         , m_hasXHeight(false)
         , m_hasZeroWidth(false)
     {
     }
 
     unsigned unitsPerEm() const { return m_unitsPerEm; }
     void setUnitsPerEm(unsigned unitsPerEm) { m_unitsPerEm = unitsPerEm; }
 
     float floatAscent(FontBaseline baselineType = AlphabeticBaseline) const
     {
@@ skipping 65 matching lines @@
     float zeroWidth() const { return m_zeroWidth; }
     void setZeroWidth(float zeroWidth)
     {
         m_zeroWidth = zeroWidth;
         m_hasZeroWidth = true;
     }
 
     bool hasZeroWidth() const { return m_hasZeroWidth; }
     void setHasZeroWidth(bool hasZeroWidth) { m_hasZeroWidth = hasZeroWidth; }
 
+    float underlineThickness() const { return m_underlinethickness; }
+    void setUnderlineThickness(float underlineThickness) { m_underlinethickness = underlineThickness; }
+
 private:
     friend class SimpleFontData;
 
     void reset()
     {
         m_unitsPerEm = gDefaultUnitsPerEm;
         m_ascent = 0;
         m_descent = 0;
         m_lineGap = 0;
         m_lineSpacing = 0;
         m_xHeight = 0;
         m_hasXHeight = false;
+        m_underlinethickness = 0;
     }
 
     unsigned m_unitsPerEm;
     float m_ascent;
     float m_descent;
     float m_lineGap;
     float m_lineSpacing;
     float m_xHeight;
     float m_zeroWidth;
+    float m_underlinethickness;
     bool m_hasXHeight;
     bool m_hasZeroWidth;
 };
 
 inline float scaleEmToUnits(float x, unsigned unitsPerEm)
 {
     return unitsPerEm ? x / unitsPerEm : x;
 }
 
 } // namespace WebCore
 
 #endif // FontMetrics_h