Introduce a SVGUnknownElement class for unknown SVG elements

Source/core/svg/SVGFontFaceUriElement.h

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.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 26 matching lines @@
 
     PassRefPtr<CSSFontFaceSrcValue> srcValue() const;
 
 private:
     SVGFontFaceUriElement(const QualifiedName&, Document*);
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
 
+    virtual bool rendererIsNeeded(const NodeRenderingContext&) OVERRIDE { return false; }
+
     void loadFont();
 
     ResourcePtr<CachedFont> m_cachedFont;
 };
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG_FONTS)
 #endif
 
 // vim:ts=4:noet