Fix sky include guards to match Chromium style

sky/engine/core/css/Pair.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, 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 Pair_h
-#define Pair_h
+#ifndef SKY_ENGINE_CORE_CSS_PAIR_H_
+#define SKY_ENGINE_CORE_CSS_PAIR_H_
 
 #include "sky/engine/core/css/CSSPrimitiveValue.h"
 #include "sky/engine/wtf/PassRefPtr.h"
 #include "sky/engine/wtf/RefCounted.h"
 #include "sky/engine/wtf/text/StringBuilder.h"
 
 namespace blink {
 
 // A primitive value representing a pair.  This is useful for properties like border-radius, background-size/position,
 // and border-spacing (all of which are space-separated sets of two values).  At the moment we are only using it for
@@ skipping 47 matching lines @@
         return first + ' ' + second;
     }
 
     RefPtr<CSSPrimitiveValue> m_first;
     RefPtr<CSSPrimitiveValue> m_second;
     IdenticalValuesPolicy m_identicalValuesPolicy;
 };
 
 } // namespace
 
-#endif
+#endif  // SKY_ENGINE_CORE_CSS_PAIR_H_