Move scoped_nsdisable_screen_update from base to app/mac...

app/mac/scoped_nsdisable_screen_updates.h

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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 BASE_SCOPED_NSDISABLE_SCREEN_UPDATES_H_
-#define BASE_SCOPED_NSDISABLE_SCREEN_UPDATES_H_
+#ifndef APP_MAC_SCOPED_NSDISABLE_SCREEN_UPDATES_H_
+#define APP_MAC_SCOPED_NSDISABLE_SCREEN_UPDATES_H_
 #pragma once
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 
-namespace base {
+namespace app {
+namespace mac {
 
 // A stack-based class to disable Cocoa screen updates. When instantiated, it
 // disables screen updates and enables them when destroyed. Update disabling
 // can be nested, and there is a time-maximum (about 1 second) after which
 // Cocoa will automatically re-enable updating. This class doesn't attempt to
 // overrule that.
-
 class ScopedNSDisableScreenUpdates {
  public:
   ScopedNSDisableScreenUpdates() {
     NSDisableScreenUpdates();
   }
   ~ScopedNSDisableScreenUpdates() {
     NSEnableScreenUpdates();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScopedNSDisableScreenUpdates);
 };
 
-}  // namespace
+}  // namespace mac
+}  // namespace app
 
-#endif  // BASE_SCOPED_NSDISABLE_SCREEN_UPDATES_H_
+#endif  // APP_MAC_SCOPED_NSDISABLE_SCREEN_UPDATES_H_