Clean up forward declarations in Source/platform

Source/platform/fonts/FontPlatformData.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc.
  * Copyright (C) 2006 Michael Emmel mike.emmel@gmail.com
  * Copyright (C) 2007 Holger Hans Peter Freyther
  * Copyright (C) 2007 Pioneer Research Center USA, Inc.
  * Copyright (C) 2010, 2011 Brent Fulgham <bfulgham@webkit.org>
  *
  * 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
@@ skipping 43 matching lines @@
 #include "third_party/skia/include/core/SkTypeface.h"
 
 typedef struct CGFont* CGFontRef;
 typedef const struct __CTFont* CTFontRef;
 typedef UInt32 FMFont;
 typedef FMFont ATSUFontID;
 typedef UInt32 ATSFontRef;
 
 namespace blink {
 
-class FontDescription;
-class SharedBuffer;
-
 class HarfBuzzFace;
 
 inline CTFontRef toCTFontRef(NSFont *nsFont) { return reinterpret_cast<CTFontRef>(nsFont); }
 
 class PLATFORM_EXPORT FontPlatformData {
 public:
     FontPlatformData(WTF::HashTableDeletedValueType);
     FontPlatformData();
     FontPlatformData(const FontPlatformData&);
     FontPlatformData(float size, bool syntheticBold, bool syntheticOblique, FontOrientation = Horizontal, FontWidthVariant = RegularWidth);
@@ skipping 92 matching lines @@
 
     bool m_isColorBitmapFont;
     bool m_isCompositeFontReference;
 };
 
 } // namespace blink
 
 #endif // FontPlatformData_h
 
 #endif