Improve RAII of StyleResolverState.

Source/core/css/resolver/FontBuilder.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2013 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.
  *
@@ skipping 23 matching lines @@
 class CSSValue;
 class FontSelector;
 class RenderStyle;
 
 class FontDescriptionChangeScope;
 
 class FontBuilder {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(FontBuilder);
 public:
-    FontBuilder(const Document&);
+    FontBuilder(const Document&, RenderStyle*);
 
-    void setStyle(RenderStyle* style) { m_style = style; }
     void setInitial(float effectiveZoom);
 
     void didChangeFontParameters(bool);
 
     void inheritFrom(const FontDescription&);
 
     FontFamily standardFontFamily() const;
     AtomicString standardFontFamilyName() const;
     AtomicString genericFontFamilyName(FontDescription::GenericFamilyType) const;
 
@@ skipping 61 matching lines @@
     // is changed, FontBuilder tracks the need to update
     // style->font() with this bool.
     bool m_fontDirty;
 
     friend class FontBuilderTest;
 };
 
 }
 
 #endif