Consider slots as a focus scope

third_party/WebKit/Source/core/dom/CombinedNodeTraversal.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
- * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
- * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
+ * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2014 Samsung Electronics. 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.
+ *
  */
 
-#include "HTMLTagCollection.h"
+#ifndef CombinedNodeTraversal_h
+#define CombinedNodeTraversal_h
+
+#include "core/dom/Node.h"
+#include "core/html/HTMLSlotElement.h"
 
 namespace blink {
 
-HTMLTagCollection::HTMLTagCollection(ContainerNode& rootNode, const AtomicString& localName)
-    : TagCollection(rootNode, HTMLTagCollectionType, starAtom, localName)
-    , m_loweredLocalName(localName.lower())
-{
-    ASSERT(rootNode.document().isHTMLDocument());
+class CombinedNodeTraversal {
+    public:
+        Node* next();
+        Node* previous();
+        Node* customReturnForNext();
+        Node* customReturnForPrevious();
+        CombinedNodeTraversal(const Node& start);
+
+    private:
+        RefPtrWillBePersistent<Node> m_currentNode;
+        bool m_traversingAssignedNodes;
+}; // namespace blink
 }
 
-} // namespace blink
+#endif