Consistently use AtomicString for namespaceURI / prefix

Source/core/xml/XPathStep.h

 /*
  * Copyright (C) 2005 Frerich Raabe <raabe@kde.org>
  * Copyright (C) 2006, 2009 Apple 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 41 matching lines @@
 
     class NodeTest {
         WTF_MAKE_FAST_ALLOCATED;
     public:
         enum Kind {
             TextNodeTest, CommentNodeTest, ProcessingInstructionNodeTest, AnyNodeTest, NameTest
         };
 
         NodeTest(Kind kind) : m_kind(kind) { }
         NodeTest(Kind kind, const String& data) : m_kind(kind), m_data(data) { }
-        NodeTest(Kind kind, const String& data, const String& namespaceURI) : m_kind(kind), m_data(data), m_namespaceURI(namespaceURI) { }
+        NodeTest(Kind kind, const AtomicString& data, const AtomicString& namespaceURI) : m_kind(kind), m_data(data), m_namespaceURI(namespaceURI) { }
 
         NodeTest(const NodeTest& o)
             : m_kind(o.m_kind)
             , m_data(o.m_data)
             , m_namespaceURI(o.m_namespaceURI)
         {
             ASSERT(o.m_mergedPredicates.isEmpty());
         }
         NodeTest& operator=(const NodeTest& o)
         {
@@ skipping 43 matching lines @@
     Vector<OwnPtr<Predicate> > m_predicates;
 };
 
 void optimizeStepPair(Step*, Step*, bool& dropSecondStep);
 
 } // namespace XPath
 
 } // namespace WebCore
 
 #endif // XPathStep_h