Remove Mac native font type members from FontPlatformData

Source/web/mac/WebSubstringUtil.mm

 /*
  * Copyright (C) 2005, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2011 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.
@@ skipping 60 matching lines @@
         if (!numCharacters)
             continue;
 
         Node* container = it.startContainer();
         RenderObject* renderer = container->renderer();
         ASSERT(renderer);
         if (!renderer)
             continue;
 
         RenderStyle* style = renderer->style();
-        NSFont* font = style->font().primaryFont()->getNSFont();
+        // TODO(dro): Check whether we can really use the CTFont here.
+        const NSFont* font = style->font().primaryFont()->getNSFont();
         // If the platform font can't be loaded, it's likely that the site is
         // using a web font. For now, just use the default font instead.
         // TODO(rsesek): Change the font activation flags to allow other processes
         // to use the font.
         if (!font)
           font = [NSFont systemFontOfSize:style->font().fontDescription().computedSize()];
         [attrs setObject:font forKey:NSFontAttributeName];
 
         if (style->visitedDependentColor(CSSPropertyColor).alpha())
             [attrs setObject:nsColor(style->visitedDependentColor(CSSPropertyColor)) forKey:NSForegroundColorAttributeName];
@@ skipping 66 matching lines @@
     if (!editable)
         return nil;
     RefPtrWillBeRawPtr<Range> range(PlainTextRange(location, location + length).createRange(*editable));
     if (!range)
         return nil;
 
     return attributedSubstringFromRange(range.get());
 }
 
 } // namespace blink