chromeos: Move files in //ash/common to //ash, part 1

ash/system/supervised/custodian_info_tray_observer.h

 // Copyright 2014 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_COMMON_SYSTEM_CHROMEOS_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_
+#ifndef ASH_SYSTEM_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_
+#define ASH_SYSTEM_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_
 
 namespace ash {
 
 // Used to observe SystemTrayDelegate.
 class CustodianInfoTrayObserver {
  public:
   // Called when information about the supervised user's custodian is changed,
   // e.g. the display name.
   virtual void OnCustodianInfoChanged() = 0;
 
  protected:
   virtual ~CustodianInfoTrayObserver() {}
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_
+#endif  // ASH_SYSTEM_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_