Fix sky include guards to match Chromium style

sky/engine/core/html/HTMLDocument.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009 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 HTMLDocument_h
-#define HTMLDocument_h
+#ifndef SKY_ENGINE_CORE_HTML_HTMLDOCUMENT_H_
+#define SKY_ENGINE_CORE_HTML_HTMLDOCUMENT_H_
 
 #include "sky/engine/core/dom/Document.h"
 
 namespace blink {
 
 // FIXME(sky): Merge into Document.
 class HTMLDocument : public Document {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtr<HTMLDocument> create(const DocumentInit& initializer = DocumentInit())
     {
         return adoptRef(new HTMLDocument(initializer));
     }
     virtual ~HTMLDocument();
 
 protected:
     HTMLDocument(const DocumentInit&, DocumentClassFlags extendedDocumentClasses = DefaultDocumentClass);
 };
 
 DEFINE_DOCUMENT_TYPE_CASTS(HTMLDocument);
 
 } // namespace blink
 
-#endif // HTMLDocument_h
+#endif  // SKY_ENGINE_CORE_HTML_HTMLDOCUMENT_H_