ash uber tray: Allow customizing each item depending on whether the user is logged in or not.

ash/system/user/login_status.h

+// Copyright (c) 2012 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_USER_LOGIN_STATUS_H_
+#define ASH_SYSTEM_USER_LOGIN_STATUS_H_
+
+namespace ash {
+namespace user {
+
+enum LoginStatus {
+  LOGGED_IN_USER,   // A normal user is logged in.
+  LOGGED_IN_OWNER,  // The owner of the device is logged in.
+  LOGGED_IN_GUEST,  // A guest is logged in (i.e. incognito)
+  LOGGED_IN_NONE,   // Not logged in.
+};
+
+}  // namespace user
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_USER_LOGIN_STATUS_H_