Remove some dead code in SVG "mixins"

third_party/WebKit/Source/core/svg/SVGURIReference.h

 /*
  * Copyright (C) 2004, 2005, 2008, 2009 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.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
  * 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 17 matching lines @@
 
 namespace blink {
 
 class Element;
 
 class CORE_EXPORT SVGURIReference : public WillBeGarbageCollectedMixin {
 public:
     virtual ~SVGURIReference() { }
 
     bool isKnownAttribute(const QualifiedName&);
-    void addSupportedAttributes(HashSet<QualifiedName>&);
 
     static AtomicString fragmentIdentifierFromIRIString(const String&, const TreeScope&);
     static Element* targetElementFromIRIString(const String&, const TreeScope&, AtomicString* = 0, Document* = 0);
 
     static inline bool isExternalURIReference(const String& uri, const Document& document)
     {
         // Fragment-only URIs are always internal
         if (uri.startsWith('#'))
             return false;
 
@@ skipping 12 matching lines @@
 protected:
     explicit SVGURIReference(SVGElement*);
 
 private:
     RefPtrWillBeMember<SVGAnimatedString> m_href;
 };
 
 } // namespace blink
 
 #endif // SVGURIReference_h