Introduce isHTMLAreaElement and toHTMLAreaElement

Source/core/html/HTMLAreaElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2008, 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 50 matching lines @@
     enum Shape { Default, Poly, Rect, Circle, Unknown };
     Path getRegion(const LayoutSize&) const;
     void invalidateCachedRegion();
 
     OwnPtr<Path> m_region;
     Vector<Length> m_coords;
     LayoutSize m_lastSize;
     Shape m_shape;
 };
 
+inline bool isHTMLAreaElement(const Node* node)
+{
+    return node->hasTagName(HTMLNames::areaTag);
+}
+
+inline bool isHTMLAreaElement(const Element* element)
+{
+    return element->hasTagName(HTMLNames::areaTag);
+}
+
+inline HTMLAreaElement* toHTMLAreaElement(Node* node)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!node || isHTMLAreaElement(node));
+    return static_cast<HTMLAreaElement*>(node);
+}
+
 } //namespace
 
 #endif