Consistently use AtomicString for namespaceURI / prefix

Source/core/xml/XPathParser.h

 /*
  * Copyright 2005 Maksim Orlovich <maksim@kde.org>
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 44 matching lines @@
     Token(int t, EqTestOp::Opcode v): type(t), eqop(v) { }
 };
 
 class Parser {
     WTF_MAKE_NONCOPYABLE(Parser);
 public:
     Parser();
     ~Parser();
 
     XPathNSResolver* resolver() const { return m_resolver.get(); }
-    bool expandQName(const String& qName, String& localName, String& namespaceURI);
+    bool expandQName(const String& qName, AtomicString& localName, AtomicString& namespaceURI);
 
     Expression* parseStatement(const String& statement, PassRefPtr<XPathNSResolver>, ExceptionState&);
 
     static Parser* current() { return currentParser; }
 
     int lex(void* yylval);
 
     Expression* m_topExpr;
     bool m_gotNamespaceError;
 
@@ skipping 44 matching lines @@
     HashSet<Vector<OwnPtr<Expression> >*> m_expressionVectors;
     HashSet<String*> m_strings;
     HashSet<Step::NodeTest*> m_nodeTests;
 };
 
 } // XPath
 
 } // WebCore
 
 #endif