[SVG2] Add tabindex handling in svg.

Source/core/html/HTMLAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2009, 2011 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 221 matching lines @@
     if (!isFocusable())
         return;
 
     HTMLImageElement* imageElement = this->imageElement();
     if (!imageElement)
         return;
 
     imageElement->updateFocusAppearance(restorePreviousSelection);
 }
 
-bool HTMLAreaElement::supportsFocus() const
-{
-    // If the AREA element was a link, it should support focus.
-    // FIXME: This means that an AREA that is not a link cannot be made focusable through contenteditable or tabindex. Is it correct?
-    return isLink();
 }
-
-}