StringImpl should not be referred from StringImplCF.

Source/platform/mac/ThemeMac.mm

 /*
  * Copyright (C) 2008, 2010, 2011, 2012 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 557 matching lines @@
 
 FontDescription ThemeMac::controlFont(ControlPart part, const FontDescription& fontDescription, float zoomFactor) const
 {
     switch (part) {
         case PushButtonPart: {
             FontDescription result;
             result.setIsAbsoluteSize(true);
             result.setGenericFamily(FontDescription::SerifFamily);
 
             NSFont* nsFont = [NSFont systemFontOfSize:[NSFont systemFontSizeForControlSize:controlSizeForFont(fontDescription)]];
-            result.firstFamily().setFamily([nsFont webCoreFamilyName]);
+            NSString* nsFamilyName = [nsFont webCoreFamilyName];
+            result.firstFamily().setFamily(AtomicString([nsFamilyName UTF8String]));
             result.setComputedSize([nsFont pointSize] * zoomFactor);
             result.setSpecifiedSize([nsFont pointSize] * zoomFactor);
             return result;
         }
         default:
             return Theme::controlFont(part, fontDescription, zoomFactor);
     }
 }
 
 LengthSize ThemeMac::controlSize(ControlPart part, const FontDescription& fontDescription, const LengthSize& zoomedSize, float zoomFactor) const
@@ skipping 130 matching lines @@
             break;
         case InnerSpinButtonPart:
             paintStepper(states, context, zoomedRect, zoomFactor, scrollView);
             break;
         default:
             break;
     }
 }
 
 }