Consider slots as a focus scope

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

Index: third_party/WebKit/Source/core/dom/CombinedNodeTraversal.cpp
diff --git a/third_party/WebKit/Source/core/dom/CombinedNodeTraversal.cpp b/third_party/WebKit/Source/core/dom/CombinedNodeTraversal.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6db68595f56db3a78a34d873b0fc69aa2e098bf0
--- /dev/null
+++ b/third_party/WebKit/Source/core/dom/CombinedNodeTraversal.cpp
@@ -0,0 +1,80 @@
+/*
+ * 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, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
+ *
+ * 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 "core/dom/CombinedNodeTraversal.h"
+
+#include "core/dom/AssignedNodeTraversal.h"
+#include "core/dom/Element.h"
+#include "core/dom/ElementTraversal.h"
+#include "core/dom/NodeTraversal.h"
+#include "core/dom/shadow/ElementShadow.h"
+#include "core/dom/shadow/ShadowRoot.h"
+#include "core/html/HTMLSlotElement.h"
+
+namespace blink {
+CombinedNodeTraversal::CombinedNodeTraversal(const Node& start)
+    : m_currentNode(const_cast<Node*>(&start))
+    , m_traversingAssignedNodes(AssignedNodeTraversal::isInAssignedScope(*m_currentNode))
+{
+}
+
+Node* CombinedNodeTraversal::next()
+{
+    if (m_traversingAssignedNodes) {
+        m_currentNode = AssignedNodeTraversal::next(*m_currentNode);
+    } else {
+        m_currentNode = NodeTraversal::next(*m_currentNode);
+    }
+    return customReturnForNext();
+}
+
+Node* CombinedNodeTraversal::previous()
+{
+    if (m_traversingAssignedNodes) {
+        m_currentNode = AssignedNodeTraversal::previous(*m_currentNode);
+    } else {
+        m_currentNode = NodeTraversal::previous(*m_currentNode);
+    }
+    return customReturnForPrevious();
+}
+
+Node* CombinedNodeTraversal::customReturnForNext()
+{
+    if (!m_currentNode)
+        return nullptr;
+    if (m_currentNode->isTextNode() || (!m_traversingAssignedNodes && AssignedNodeTraversal::isInAssignedScope(*m_currentNode)))
+        return next();
+    return m_currentNode.get();
+}
+
+Node* CombinedNodeTraversal::customReturnForPrevious()
+{
+    if (!m_currentNode)
+        return nullptr;
+    if (m_currentNode->isTextNode() || (!m_traversingAssignedNodes && AssignedNodeTraversal::isInAssignedScope(*m_currentNode)))
+        return previous();
+    return m_currentNode.get();
+}
+
+} // namespace blink