Introduce a SVGUnknownElement class for unknown SVG elements

Source/core/svg/SVGPatternElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 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 44 matching lines @@
     SVGPatternElement(const QualifiedName&, Document*);
 
     virtual bool isValid() const { return SVGTests::isValid(); }
     virtual bool needsPendingResourceHandling() const { return false; }
 
     bool isSupportedAttribute(const QualifiedName&);
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual void svgAttributeChanged(const QualifiedName&);
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
 
-    virtual bool rendererIsNeeded(const NodeRenderingContext& context) OVERRIDE { return rendererIsNeededInternal(context); }
     virtual RenderObject* createRenderer(RenderStyle*);
 
     virtual bool selfHasRelativeLengths() const;
 
     BEGIN_DECLARE_ANIMATED_PROPERTIES(SVGPatternElement)
         DECLARE_ANIMATED_LENGTH(X, x)
         DECLARE_ANIMATED_LENGTH(Y, y)
         DECLARE_ANIMATED_LENGTH(Width, width)
         DECLARE_ANIMATED_LENGTH(Height, height)
         DECLARE_ANIMATED_ENUMERATION(PatternUnits, patternUnits, SVGUnitTypes::SVGUnitType)
@@ skipping 13 matching lines @@
 
 inline SVGPatternElement* toSVGPatternElement(Node* node)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(SVGNames::patternTag));
     return static_cast<SVGPatternElement*>(node);
 }
 
 } // namespace WebCore
 
 #endif