Fix sky include guards to match Chromium style

sky/engine/wtf/HashTraits.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 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 WTF_HashTraits_h
-#define WTF_HashTraits_h
+#ifndef SKY_ENGINE_WTF_HASHTRAITS_H_
+#define SKY_ENGINE_WTF_HASHTRAITS_H_
 
 #include <string.h> // For memset.
 #include <limits>
 #include <utility>
 #include "sky/engine/wtf/HashFunctions.h"
 #include "sky/engine/wtf/HashTableDeletedValueType.h"
 #include "sky/engine/wtf/StdLibExtras.h"
 #include "sky/engine/wtf/TypeTraits.h"
 
 namespace WTF {
@@ skipping 280 matching lines @@
     template<WeakHandlingFlag weakHandlingFlag, ShouldWeakPointersBeMarkedStrongly strongify, typename T, typename Traits>
     struct TraceInCollectionTrait;
 
 } // namespace WTF
 
 using WTF::HashTraits;
 using WTF::PairHashTraits;
 using WTF::NullableHashTraits;
 using WTF::SimpleClassHashTraits;
 
-#endif // WTF_HashTraits_h
+#endif  // SKY_ENGINE_WTF_HASHTRAITS_H_