Switch to HarfBuzz on Mac and remove CoreText shaper

Source/platform/fonts/Font.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Holger Hans Peter Freyther
  *
  * 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
@@ skipping 109 matching lines @@
     int emphasisMarkAscent(const AtomicString&) const;
     int emphasisMarkDescent(const AtomicString&) const;
     int emphasisMarkHeight(const AtomicString&) const;
 
     const SimpleFontData* primaryFont() const;
     const FontData* fontDataAt(unsigned) const;
     inline GlyphData glyphDataForCharacter(UChar32& c, bool mirror, bool spaceNormalize = false, FontDataVariant variant = AutoVariant) const
     {
         return glyphDataAndPageForCharacter(c, mirror, spaceNormalize, variant).first;
     }
-#if OS(MACOSX)
-    const SimpleFontData* fontDataForCombiningCharacterSequence(const UChar*, size_t length, FontDataVariant) const;
-#endif
+
     std::pair<GlyphData, GlyphPage*> glyphDataAndPageForCharacter(UChar32&, bool mirror, bool normalizeSpace = false, FontDataVariant = AutoVariant) const;
     bool primaryFontHasGlyphForCharacter(UChar32) const;
 
     CodePath codePath(const TextRun&) const;
 
     PassTextBlobPtr buildTextBlob(const TextRunPaintInfo&, const FloatPoint& textOrigin, bool couldUseLCDRenderedText, CustomFontNotReadyAction = DoNotPaintIfFontNotReady) const;
     void drawTextBlob(GraphicsContext*, const SkTextBlob*, const SkPoint& origin) const;
 
 private:
     enum ForTextEmphasisOrNot { NotForTextEmphasis, ForTextEmphasis };
@@ skipping 84 matching lines @@
 {
     if (!tabSize)
         return fontDescription().letterSpacing();
     float tabWidth = tabSize * fontData.spaceWidth() + fontDescription().letterSpacing();
     return tabWidth - fmodf(position, tabWidth);
 }
 
 } // namespace blink
 
 #endif