Reland "Add plumbing for font-stretch"

Source/core/css/CSSFontValue.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple 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,
@@ skipping 28 matching lines @@
 
     String customCSSText() const;
 
     bool equals(const CSSFontValue&) const;
 
     void traceAfterDispatch(Visitor*);
 
     RefPtrWillBeMember<CSSPrimitiveValue> style;
     RefPtrWillBeMember<CSSPrimitiveValue> variant;
     RefPtrWillBeMember<CSSPrimitiveValue> weight;
+    RefPtrWillBeMember<CSSPrimitiveValue> stretch;
     RefPtrWillBeMember<CSSPrimitiveValue> size;
     RefPtrWillBeMember<CSSPrimitiveValue> lineHeight;
     RefPtrWillBeMember<CSSValueList> family;
 
 private:
     CSSFontValue()
         : CSSValue(FontClass)
     {
     }
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSFontValue, isFontValue());
 
 } // namespace
 
 #endif