Add template parameter to ElementTraversal to iterate over Elements of a specific type

Source/core/dom/Traversal.h

-/*
- * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
- * Copyright (C) 2000 Frederik Holljen (frederik.holljen@hig.no)
- * Copyright (C) 2001 Peter Kelly (pmk@post.com)
- * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
- * Copyright (C) 2004, 2008 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.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public License
- * along with this library; see the file COPYING.LIB.  If not, write to
- * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA 02110-1301, USA.
- *
- */
-
-#ifndef Traversal_h
-#define Traversal_h
-
-#include "bindings/v8/ScriptState.h"
-#include "wtf/RefPtr.h"
-
-namespace WebCore {
-
-    class Node;
-    class NodeFilter;
-
-    class Traversal {
-    public:
-        Node* root() const { return m_root.get(); }
-        unsigned whatToShow() const { return m_whatToShow; }
-        NodeFilter* filter() const { return m_filter.get(); }
-        // |expandEntityReferences| first appeared in "DOM Level 2 Traversal and Range". However, this argument was
-        // never implemented, and, in DOM4, the function argument |expandEntityReferences| is removed from
-        // Document.createNodeIterator() and Document.createTreeWalker().
-        bool expandEntityReferences() const { return false; }
-
-    protected:
-        Traversal(PassRefPtr<Node>, unsigned whatToShow, PassRefPtr<NodeFilter>);
-        short acceptNode(ScriptState*, Node*) const;
-
-    private:
-        RefPtr<Node> m_root;
-        unsigned m_whatToShow;
-        RefPtr<NodeFilter> m_filter;
-    };
-
-} // namespace WebCore
-
-#endif // Traversal_h