Include AvailabilityMacros.h only where it is used.

Source/core/platform/graphics/cocoa/FontPlatformDataCocoa.mm

 /*
  * This file is part of the internal font implementation.
  *
  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #import "config.h"
 #import "core/platform/graphics/FontPlatformData.h"
 
 #import <AppKit/NSFont.h>
+#import <AvailabilityMacros.h>
 #import <wtf/text/WTFString.h>
 
 #if OS(DARWIN)
 #import "core/platform/graphics/harfbuzz/HarfBuzzFace.h"
 #endif
 
 namespace WebCore {
 
 // These CoreText Text Spacing feature selectors are not defined in CoreText.
 enum TextSpacingCTFeatureSelector { TextSpacingProportional, TextSpacingFullWidth, TextSpacingHalfWidth, TextSpacingThirdWidth, TextSpacingQuarterWidth };
@@ skipping 268 matching lines @@
 #ifndef NDEBUG
 String FontPlatformData::description() const
 {
     RetainPtr<CFStringRef> cgFontDescription(AdoptCF, CFCopyDescription(cgFont()));
     return String(cgFontDescription.get()) + " " + String::number(m_size)
             + (m_syntheticBold ? " synthetic bold" : "") + (m_syntheticOblique ? " synthetic oblique" : "") + (m_orientation ? " vertical orientation" : "");
 }
 #endif
 
 } // namespace WebCore