sky/engine updates for iOS targets

sky/engine/platform/fonts/skia/SimpleFontDataSkia.cpp

 /*
  * Copyright (c) 2008, 2009, 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 50 matching lines @@
     SkPaint::FontMetrics metrics;
 
     m_platformData.setupPaint(&paint);
     paint.getFontMetrics(&metrics);
     SkTypeface* face = paint.getTypeface();
     ASSERT(face);
 
     int vdmxAscent = 0, vdmxDescent = 0;
     bool isVDMXValid = false;
 
-#if OS(LINUX) || OS(ANDROID)
+#if OS(LINUX) || OS(ANDROID) || OS(IOS)
     // Manually digging up VDMX metrics is only applicable when bytecode hinting using FreeType.
     // With GDI, the metrics will already have taken this into account (as needed).
     // With DirectWrite or CoreText, no bytecode hinting is ever done.
     // This code should be pushed into FreeType (hinted font metrics).
     static const uint32_t vdmxTag = SkSetFourByteTag('V', 'D', 'M', 'X');
     int pixelSize = m_platformData.size() + 0.5;
     if (!paint.isAutohinted()
         &&    (paint.getHinting() == SkPaint::kFull_Hinting
             || paint.getHinting() == SkPaint::kNormal_Hinting))
     {
@@ skipping 13 matching lines @@
     float descent;
 
     // Beware those who step here: This code is designed to match Win32 font
     // metrics *exactly* (except the adjustment of ascent/descent on Linux/Android).
     if (isVDMXValid) {
         ascent = vdmxAscent;
         descent = -vdmxDescent;
     } else {
         ascent = SkScalarRoundToInt(-metrics.fAscent);
         descent = SkScalarRoundToInt(metrics.fDescent);
-#if OS(LINUX) || OS(ANDROID)
+#if OS(LINUX) || OS(ANDROID) || OS(IOS)
         // When subpixel positioning is enabled, if the descent is rounded down, the descent part
         // of the glyph may be truncated when displayed in a 'overflow: hidden' container.
         // To avoid that, borrow 1 unit from the ascent when possible.
         // FIXME: This can be removed if sub-pixel ascent/descent is supported.
         if (platformData().fontRenderStyle().useSubpixelPositioning && descent < SkScalarToFloat(metrics.fDescent) && ascent >= 1) {
             ++descent;
             --ascent;
         }
 #endif
     }
@@ skipping 177 matching lines @@
         if (glyphs[i]) {
             pageToFill->setGlyphDataForIndex(offset + i, glyphs[i], this);
             haveGlyphs = true;
         }
     }
 
     return haveGlyphs;
 }
 
 } // namespace blink