Have const StyleResolverState return const RenderStyle

Source/core/css/resolver/FontBuilder.cpp

 /*
  * 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 263 matching lines @@
 {
     return size * 1.2f;
 }
 
 static float smallerFontSize(float size)
 {
     return size / 1.2f;
 }
 
 // FIXME: Have to pass RenderStyles here for calc/computed values. This shouldn't be neecessary.
-void FontBuilder::setFontSizeValue(CSSValue* value, RenderStyle* parentStyle, RenderStyle* rootElementStyle, float effectiveZoom)
+void FontBuilder::setFontSizeValue(CSSValue* value, RenderStyle* parentStyle, const RenderStyle* rootElementStyle, float effectiveZoom)
 {
     if (!value->isPrimitiveValue())
         return;
 
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
 
     FontDescriptionChangeScope scope(this);
 
     scope.fontDescription().setKeywordSize(0);
     float parentSize = 0;
@@ skipping 368 matching lines @@
     FontOrientation fontOrientation;
     NonCJKGlyphOrientation glyphOrientation;
     getFontAndGlyphOrientation(documentStyle, fontOrientation, glyphOrientation);
     fontDescription.setOrientation(fontOrientation);
     fontDescription.setNonCJKGlyphOrientation(glyphOrientation);
     documentStyle->setFontDescription(fontDescription);
     documentStyle->font().update(fontSelector);
 }
 
 }