Adding infrastructure for possibility of changing manager names for the supervised accounts.

ash/system/chromeos/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_SYSTEM_CHROMEOS_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_
+#define ASH_SYSTEM_CHROMEOS_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_SYSTEM_CHROMEOS_SUPERVISED_CUSTODIAN_INFO_TRAY_OBSERVER_H_