Fix sky include guards to match Chromium style

sky/engine/core/rendering/RenderLayerStackingNode.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 24 matching lines @@
  * applicable instead of those above.  If you wish to allow use of your
  * version of this file only under the terms of one of those two
  * licenses (the MPL or the GPL) and not to allow others to use your
  * version of this file under the LGPL, indicate your decision by
  * deletingthe provisions above and replace them with the notice and
  * other provisions required by the MPL or the GPL, as the case may be.
  * If you do not delete the provisions above, a recipient may use your
  * version of this file under any of the LGPL, the MPL or the GPL.
  */
 
-#ifndef RenderLayerStackingNode_h
-#define RenderLayerStackingNode_h
+#ifndef SKY_ENGINE_CORE_RENDERING_RENDERLAYERSTACKINGNODE_H_
+#define SKY_ENGINE_CORE_RENDERING_RENDERLAYERSTACKINGNODE_H_
 
 #include "sky/engine/core/rendering/RenderLayerModelObject.h"
 #include "sky/engine/wtf/Noncopyable.h"
 #include "sky/engine/wtf/OwnPtr.h"
 #include "sky/engine/wtf/Vector.h"
 
 namespace blink {
 
 class RenderLayer;
 class RenderLayerCompositor;
@@ skipping 153 matching lines @@
     }
 
 private:
     RenderLayerStackingNode* m_stackingNode;
     bool m_previousMutationAllowedState;
 };
 #endif
 
 } // namespace blink
 
-#endif // RenderLayerStackingNode_h
+#endif  // SKY_ENGINE_CORE_RENDERING_RENDERLAYERSTACKINGNODE_H_