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

Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 356 matching lines @@
 {
     return getNameAttribute();
 }
 
 short HTMLAnchorElement::tabIndex() const
 {
     // Skip the supportsFocus check in HTMLElement.
     return Element::tabIndex();
 }
 
-String HTMLAnchorElement::target() const
+AtomicString HTMLAnchorElement::target() const
 {
     return getAttribute(targetAttr);
 }
 
 
 String HTMLAnchorElement::text()
 {
     return innerText();
 }
 
@@ skipping 301 matching lines @@
     preconnectToURL(url, motivation);
     m_hasIssuedPreconnect = true;
 }
 
 bool HTMLAnchorElement::isInteractiveContent() const
 {
     return true;
 }
 
 }