Fix sky include guards to match Chromium style

sky/engine/core/css/SelectorChecker.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. 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 SelectorChecker_h
-#define SelectorChecker_h
+#ifndef SKY_ENGINE_CORE_CSS_SELECTORCHECKER_H_
+#define SKY_ENGINE_CORE_CSS_SELECTORCHECKER_H_
 
 #include "sky/engine/core/css/CSSSelector.h"
 #include "sky/engine/core/dom/Element.h"
 
 namespace blink {
 
 class CSSSelector;
 class ContainerNode;
 class Element;
 class RenderStyle;
@@ skipping 64 matching lines @@
     return false;
 }
 
 inline bool SelectorChecker::isHostInItsShadowTree(const Element& element, const ContainerNode* scope)
 {
     return scope && scope->isInShadowTree() && scope->shadowHost() == element;
 }
 
 }
 
-#endif
+#endif  // SKY_ENGINE_CORE_CSS_SELECTORCHECKER_H_