[SVG2] Add tabindex handling in svg.

Source/core/svg/SVGGraphicsElement.h

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2014 Google, Inc.
  *
  * 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 53 matching lines @@
 
     SVGAnimatedTransformList* transform() { return m_transform.get(); }
     const SVGAnimatedTransformList* transform() const { return m_transform.get(); }
 
     AffineTransform computeCTM(SVGElement::CTMScope mode, SVGGraphicsElement::StyleUpdateStrategy,
         const SVGGraphicsElement* ancestor = 0) const;
 
 protected:
     SVGGraphicsElement(const QualifiedName&, Document&, ConstructionType = CreateSVGElement);
 
+    virtual bool supportsFocus() const OVERRIDE { return Element::supportsFocus() || hasFocusEventListeners(); }
+
     bool isSupportedAttribute(const QualifiedName&);
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual void svgAttributeChanged(const QualifiedName&) OVERRIDE;
 
     RefPtr<SVGAnimatedTransformList> m_transform;
 
 private:
     virtual bool isSVGGraphicsElement() const OVERRIDE FINAL { return true; }
 
     // Used by <animateMotion>
     OwnPtr<AffineTransform> m_supplementalTransform;
 };
 
 inline bool isSVGGraphicsElement(const Node& node)
 {
     return node.isSVGElement() && toSVGElement(node).isSVGGraphicsElement();
 }
 
 DEFINE_ELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGGraphicsElement);
 
 } // namespace WebCore
 
 #endif // SVGGraphicsElement_h