Fix sky include guards to match Chromium style

sky/engine/wtf/text/WTFString.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 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 WTFString_h
-#define WTFString_h
+#ifndef SKY_ENGINE_WTF_TEXT_WTFSTRING_H_
+#define SKY_ENGINE_WTF_TEXT_WTFSTRING_H_
 
 // This file would be called String.h, but that conflicts with <string.h>
 // on systems without case-sensitive file systems.
 #include <string>
 
 #include "sky/engine/wtf/HashTableDeletedValueType.h"
 #include "sky/engine/wtf/WTFExport.h"
 #include "sky/engine/wtf/text/ASCIIFastPath.h"
 #include "sky/engine/wtf/text/StringImpl.h"
 #include "sky/engine/wtf/text/StringView.h"
@@ skipping 645 matching lines @@
 using WTF::charactersToDouble;
 using WTF::charactersToFloat;
 using WTF::equal;
 using WTF::equalIgnoringCase;
 using WTF::find;
 using WTF::isAllSpecialCharacters;
 using WTF::isSpaceOrNewline;
 using WTF::reverseFind;
 
 #include "sky/engine/wtf/text/AtomicString.h"
-#endif // WTFString_h
+#endif  // SKY_ENGINE_WTF_TEXT_WTFSTRING_H_