clean up coding style at ash folder.

ash/debug.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_DEBUG_H_
 #define ASH_DEBUG_H_
 
 #include "ash/ash_export.h"
 
 namespace ash {
 namespace debug {
 
 // Toggles debugging features controlled by
 // cc::LayerTreeDebugState.
 ASH_EXPORT void ToggleShowDebugBorders();
 ASH_EXPORT void ToggleShowFpsCounter();
 ASH_EXPORT void ToggleShowPaintRects();
 
-}  // debug
-}  // ash
+}  // namespace debug
+}  // namespace ash
 
 #endif  // ASH_DEBUG_H_