Introduce "navigation target classification" for spatial navigation

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 69 matching lines @@
     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;
 
     RefPtrWillBeMember<SVGAnimatedTransformList> m_transform;
 
 private:
     virtual bool isSVGGraphicsElement() const override final { return true; }
+
+    bool hasFocusEventListeners() const;
 };
 
 inline bool isSVGGraphicsElement(const SVGElement& element)
 {
     return element.isSVGGraphicsElement();
 }
 
 DEFINE_SVGELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGGraphicsElement);
 
 } // namespace blink
 
 #endif // SVGGraphicsElement_h