Rename OS(DARWIN) to OS(MACOSX).

Source/core/rendering/RenderBlockLineLayout.cpp

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google 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 839 matching lines @@
 
     LayoutUnit hyphenWidth = 0;
     if (toInlineTextBox(run->m_box)->hasHyphen()) {
         const Font& font = renderer->style(lineInfo.isFirstLine())->font();
         hyphenWidth = measureHyphenWidth(renderer, font);
     }
     float measuredWidth = 0;
 
     bool kerningIsEnabled = font.typesettingFeatures() & Kerning;
 
-#if OS(DARWIN)
+#if OS(MACOSX)
     // FIXME: Having any font feature settings enabled can lead to selection gaps on
     // Chromium-mac. https://bugs.webkit.org/show_bug.cgi?id=113418
     bool canUseSimpleFontCodePath = renderer->canUseSimpleFontCodePath() && !font.fontDescription().featureSettings();
 #else
     bool canUseSimpleFontCodePath = renderer->canUseSimpleFontCodePath();
 #endif
 
     // Since we don't cache glyph overflows, we need to re-measure the run if
     // the style is linebox-contain: glyph.
 
@@ skipping 2651 matching lines @@
     lineGridBox->alignBoxesInBlockDirection(logicalHeight(), textBoxDataMap, verticalPositionCache);
 
     setLineGridBox(lineGridBox);
 
     // FIXME: If any of the characteristics of the box change compared to the old one, then we need to do a deep dirtying
     // (similar to what happens when the page height changes). Ideally, though, we only do this if someone is actually snapping
     // to this grid.
 }
 
 }