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

Source/core/dom/ClassNodeList.h

 /*
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 David Smith (catfish.man@gmail.com)
  *
  * 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 21 matching lines @@
 
 #include "core/dom/Element.h"
 #include "core/dom/LiveNodeList.h"
 #include "core/dom/Node.h"
 #include "core/dom/SpaceSplitString.h"
 
 namespace WebCore {
 
 class ClassNodeList FINAL : public LiveNodeList {
 public:
-    static PassRefPtr<ClassNodeList> create(PassRefPtr<Node> rootNode, const String& classNames)
+    // classNames argument is an AtomicString because it is common for Elements to share the same class names.
+    // It is also used to construct a SpaceSplitString (m_classNames) and its constructor requires an AtomicString.
+    static PassRefPtr<ClassNodeList> create(PassRefPtr<Node> rootNode, CollectionType type, const AtomicString& classNames)
     {
+        ASSERT_UNUSED(type, type == ClassNodeListType);
         return adoptRef(new ClassNodeList(rootNode, classNames));
     }
 
     virtual ~ClassNodeList();
 
     bool nodeMatchesInlined(Element*) const;
 
 private:
-    ClassNodeList(PassRefPtr<Node> rootNode, const String& classNames);
+    ClassNodeList(PassRefPtr<Node> rootNode, const AtomicString& classNames);
 
     virtual bool nodeMatches(Element*) const OVERRIDE;
 
     SpaceSplitString m_classNames;
-    String m_originalClassNames;
+    AtomicString m_originalClassNames;
 };
 
 inline bool ClassNodeList::nodeMatchesInlined(Element* testNode) const
 {
     if (!testNode->hasClass())
         return false;
     if (!m_classNames.size())
         return false;
     // FIXME: DOM4 allows getElementsByClassName to return non StyledElement.
     // https://bugs.webkit.org/show_bug.cgi?id=94718
     if (!testNode->isStyledElement())
         return false;
     return testNode->classNames().containsAll(m_classNames);
 }
 
 } // namespace WebCore
 
 #endif // ClassNodeList_h