Make calls to AtomicString(const String&) explicit in web/

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 33 matching lines @@
     Path computePath(RenderObject*) const;
 
     // The parent map's image.
     HTMLImageElement* imageElement() const;
 
 private:
     explicit HTMLAreaElement(Document&);
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual bool supportsFocus() const;
-    virtual String target() const;
+    virtual AtomicString target() const OVERRIDE;
     virtual bool isKeyboardFocusable() const OVERRIDE;
     virtual bool isMouseFocusable() const;
     virtual bool rendererIsFocusable() const OVERRIDE;
     virtual void updateFocusAppearance(bool /*restorePreviousSelection*/);
     virtual void setFocus(bool) OVERRIDE;
 
     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;
 };
 
 DEFINE_NODE_TYPE_CASTS(HTMLAreaElement, hasTagName(HTMLNames::areaTag));
 
 } //namespace
 
 #endif