Fix sky include guards to match Chromium style

sky/engine/core/dom/NodeTraversal.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, 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.
  *
  */
 
-#ifndef NodeTraversal_h
-#define NodeTraversal_h
+#ifndef SKY_ENGINE_CORE_DOM_NODETRAVERSAL_H_
+#define SKY_ENGINE_CORE_DOM_NODETRAVERSAL_H_
 
 #include "sky/engine/core/dom/ContainerNode.h"
 #include "sky/engine/core/dom/Node.h"
 
 namespace blink {
 
 class NodeTraversal {
 public:
     // Does a pre-order traversal of the tree to find the next node after this one.
     // This uses the same order that tags appear in the source file. If the stayWithin
@@ skipping 90 matching lines @@
 inline Node* NodeTraversal::childAtTemplate(NodeType& parent, unsigned index)
 {
     Node* child = parent.firstChild();
     while (child && index--)
         child = child->nextSibling();
     return child;
 }
 
 } // namespace blink
 
-#endif
+#endif  // SKY_ENGINE_CORE_DOM_NODETRAVERSAL_H_