Fix sky include guards to match Chromium style

sky/engine/core/rendering/RenderLayerScrollableArea.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. 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>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 23 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 RenderLayerScrollableArea_h
-#define RenderLayerScrollableArea_h
+#ifndef SKY_ENGINE_CORE_RENDERING_RENDERLAYERSCROLLABLEAREA_H_
+#define SKY_ENGINE_CORE_RENDERING_RENDERLAYERSCROLLABLEAREA_H_
 
 #include "sky/engine/platform/scroll/ScrollableArea.h"
 
 namespace blink {
 
 class PlatformEvent;
 class RenderBox;
 class RenderLayer;
 
 class RenderLayerScrollableArea final : public ScrollableArea {
@@ skipping 134 matching lines @@
 
     IntPoint m_cachedOverlayScrollbarOffset;
 
     // For areas with overflow, we have a pair of scrollbars.
     RefPtr<Scrollbar> m_hBar;
     RefPtr<Scrollbar> m_vBar;
 };
 
 } // namespace blink
 
-#endif // RenderLayerScrollableArea_h
+#endif  // SKY_ENGINE_CORE_RENDERING_RENDERLAYERSCROLLABLEAREA_H_