Remove some dead code in SVG "mixins"

third_party/WebKit/Source/core/svg/SVGFitToViewBox.cpp

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 Rob Buis <buis@kde.org>
  * Copyright (C) 2014 Samsung Electronics. 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 78 matching lines @@
         return AffineTransform();
 
     return preserveAspectRatio->getCTM(viewBoxRect.x(), viewBoxRect.y(), viewBoxRect.width(), viewBoxRect.height(), viewWidth, viewHeight);
 }
 
 bool SVGFitToViewBox::isKnownAttribute(const QualifiedName& attrName)
 {
     return attrName == SVGNames::viewBoxAttr || attrName == SVGNames::preserveAspectRatioAttr;
 }
 
-void SVGFitToViewBox::addSupportedAttributes(HashSet<QualifiedName>& supportedAttributes)
-{
-    supportedAttributes.add(SVGNames::viewBoxAttr);
-    supportedAttributes.add(SVGNames::preserveAspectRatioAttr);
-}
-
 void SVGFitToViewBox::updateViewBox(const FloatRect& rect)
 {
     ASSERT(m_viewBox);
     m_viewBox->baseValue()->setValue(rect);
 }
 
 }