Introduce a SVGUnknownElement class for unknown SVG elements

Source/core/svg/SVGElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.org>
  * Copyright (C) 2009 Apple Inc. 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 127 matching lines @@
     SVGElement(const QualifiedName&, Document*, ConstructionType = CreateSVGElement);
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
 
     virtual void finishParsingChildren();
     virtual void attributeChanged(const QualifiedName&, const AtomicString&, AttributeModificationReason = ModifiedDirectly) OVERRIDE;
     virtual bool childShouldCreateRenderer(const NodeRenderingContext&) const OVERRIDE;
 
     virtual bool isPresentationAttribute(const QualifiedName&) const OVERRIDE;
     virtual void collectStyleForPresentationAttribute(const QualifiedName&, const AtomicString&, MutableStylePropertySet*) OVERRIDE;
-    virtual bool rendererIsNeeded(const NodeRenderingContext&) OVERRIDE { return false; }
-    bool rendererIsNeededInternal(const NodeRenderingContext&);
+    virtual bool rendererIsNeeded(const NodeRenderingContext&) OVERRIDE;
 
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
 
     static CSSPropertyID cssPropertyIdForSVGAttributeName(const QualifiedName&);
     void updateRelativeLengthsInformation() { updateRelativeLengthsInformation(selfHasRelativeLengths(), this); }
     void updateRelativeLengthsInformation(bool hasRelativeLengths, SVGElement*);
 
     virtual bool selfHasRelativeLengths() const { return false; }
@@ skipping 50 matching lines @@
 
 inline const SVGElement* toSVGElement(const Node* node)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!node || node->isSVGElement());
     return static_cast<const SVGElement*>(node);
 }
 
 }
 
 #endif