Fix sky include guards to match Chromium style

sky/engine/core/dom/DocumentParser.h

 /*
  * Copyright (C) 2000 Peter Kelly (pmk@post.com)
  * Copyright (C) 2005, 2006 Apple Computer, Inc.
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google, Inc.
  *
  * 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 DocumentParser_h
-#define DocumentParser_h
+#ifndef SKY_ENGINE_CORE_DOM_DOCUMENTPARSER_H_
+#define SKY_ENGINE_CORE_DOM_DOCUMENTPARSER_H_
 
 #include "base/callback_forward.h"
 #include "mojo/public/cpp/system/core.h"
 #include "sky/engine/platform/heap/Handle.h"
 #include "sky/engine/wtf/Forward.h"
 #include "sky/engine/wtf/RefCounted.h"
 #include "sky/engine/wtf/text/TextPosition.h"
 
 namespace blink {
 
@@ skipping 51 matching lines @@
     };
     ParserState m_state;
 
     // Every DocumentParser needs a pointer back to the document.
     // m_document will be 0 after the parser is stopped.
     Document* m_document;
 };
 
 } // namespace blink
 
-#endif // DocumentParser_h
+#endif  // SKY_ENGINE_CORE_DOM_DOCUMENTPARSER_H_