Using x-advance for emphasis mark drawing.

Source/platform/fonts/Font.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2010, 2011 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.
@@ skipping 685 matching lines @@
 inline static float offsetToMiddleOfGlyph(const SimpleFontData* fontData, Glyph glyph)
 {
     if (fontData->platformData().orientation() == Horizontal) {
         FloatRect bounds = fontData->boundsForGlyph(glyph);
         return bounds.x() + bounds.width() / 2;
     }
     // FIXME: Use glyph bounds once they make sense for vertical fonts.
     return fontData->widthForGlyph(glyph) / 2;
 }
 
-inline static float offsetToMiddleOfGlyphAtIndex(const GlyphBuffer& glyphBuffer, size_t i)
+inline static float offsetToMiddleOfAdvanceAtIndex(const GlyphBuffer& glyphBuffer, size_t i)
 {
-    return offsetToMiddleOfGlyph(glyphBuffer.fontDataAt(i), glyphBuffer.glyphAt(i));
+    return glyphBuffer.advanceAt(i) / 2;
 }
 
 void Font::drawEmphasisMarks(GraphicsContext* context, const TextRunPaintInfo& runInfo, const GlyphBuffer& glyphBuffer, const AtomicString& mark, const FloatPoint& point) const
 {
     FontCachePurgePreventer purgePreventer;
 
     GlyphData markGlyphData;
     if (!getEmphasisMarkGlyphData(mark, markGlyphData))
         return;
 
     const SimpleFontData* markFontData = markGlyphData.fontData;
     ASSERT(markFontData);
     if (!markFontData)
         return;
 
     Glyph markGlyph = markGlyphData.glyph;
     Glyph spaceGlyph = markFontData->spaceGlyph();
 
-    float middleOfLastGlyph = offsetToMiddleOfGlyphAtIndex(glyphBuffer, 0);
+    float middleOfLastGlyph = offsetToMiddleOfAdvanceAtIndex(glyphBuffer, 0);
     FloatPoint startPoint(point.x() + middleOfLastGlyph - offsetToMiddleOfGlyph(markFontData, markGlyph), point.y());
 
     GlyphBuffer markBuffer;
     for (unsigned i = 0; i + 1 < glyphBuffer.size(); ++i) {
-        float middleOfNextGlyph = offsetToMiddleOfGlyphAtIndex(glyphBuffer, i + 1);
+        float middleOfNextGlyph = offsetToMiddleOfAdvanceAtIndex(glyphBuffer, i + 1);
         float advance = glyphBuffer.advanceAt(i) - middleOfLastGlyph + middleOfNextGlyph;
         markBuffer.add(glyphBuffer.glyphAt(i) ? markGlyph : spaceGlyph, markFontData, advance);
         middleOfLastGlyph = middleOfNextGlyph;
     }
     markBuffer.add(glyphBuffer.glyphAt(glyphBuffer.size() - 1) ? markGlyph : spaceGlyph, markFontData, 0);
 
     drawGlyphBuffer(context, runInfo, markBuffer, startPoint);
 }
 
 float Font::floatWidthForSimpleText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
@@ skipping 75 matching lines @@
                 if (delta <= 0)
                     break;
             }
         }
     }
 
     return offset;
 }
 
 }