Remove isSupportedAttribute in svg

Source/core/svg/SVGTextPathElement.h

 /*
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 58 matching lines @@
     explicit SVGTextPathElement(Document&);
 
     virtual ~SVGTextPathElement();
 
     void clearResourceReferences();
 
     virtual void buildPendingResource() override;
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) override;
     virtual void removedFrom(ContainerNode*) override;
 
-    bool isSupportedAttribute(const QualifiedName&);
     virtual void svgAttributeChanged(const QualifiedName&) override;
 
     virtual LayoutObject* createLayoutObject(const ComputedStyle&) override;
     virtual bool layoutObjectIsNeeded(const ComputedStyle&) override;
 
     virtual bool selfHasRelativeLengths() const override;
 
     RefPtrWillBeMember<SVGAnimatedLength> m_startOffset;
     RefPtrWillBeMember<SVGAnimatedEnumeration<SVGTextPathMethodType>> m_method;
     RefPtrWillBeMember<SVGAnimatedEnumeration<SVGTextPathSpacingType>> m_spacing;
 };
 
 } // namespace blink
 
 #endif // SVGTextPathElement_h