Use glyph-ids for lookups of SVG font kerning-pairs

Source/core/rendering/svg/SVGTextMetrics.h

 /*
  * Copyright (C) Research In Motion Limited 2010-2012. 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGTextMetrics_h
 #define SVGTextMetrics_h
 
+#include "platform/fonts/Glyph.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class RenderSVGInlineText;
 class SVGTextLayoutAttributes;
 class TextRun;
 
 class SVGTextMetrics {
 public:
     enum MetricsType {
         SkippedSpaceMetrics
     };
 
     SVGTextMetrics();
     SVGTextMetrics(MetricsType);
-    SVGTextMetrics(RenderSVGInlineText*, unsigned position, unsigned length, float width, const String& glyphName);
+    SVGTextMetrics(RenderSVGInlineText*, unsigned position, unsigned length, float width, Glyph glyphNameGlyphId);
 
     static SVGTextMetrics measureCharacterRange(RenderSVGInlineText*, unsigned position, unsigned length);
     static TextRun constructTextRun(RenderSVGInlineText*, unsigned position, unsigned length);
 
-    bool isEmpty() const { return !m_width && !m_height && !m_glyph.isValid && m_length == 1; }
+    bool isEmpty() const { return !m_width && !m_height && m_length <= 1; }
 
     float width() const { return m_width; }
     void setWidth(float width) { m_width = width; }
 
     float height() const { return m_height; }
     unsigned length() const { return m_length; }
 
-    struct Glyph {
-        Glyph()
-            : isValid(false)
-        {
-        }
-
-        bool isValid;
-        String name;
-        String unicodeString;
-    };
-
     // Only useful when measuring individual characters, to lookup ligatures.
-    const Glyph& glyph() const { return m_glyph; }
+    Glyph glyph() const { return m_glyph; }
 
 private:
     SVGTextMetrics(RenderSVGInlineText*, const TextRun&);
 
     float m_width;
     float m_height;
     unsigned m_length;
     Glyph m_glyph;
 };
 
 } // namespace WebCore
 
 #endif