ash: Add checks for supervised users.

ash/system/chromeos/supervised/tray_supervised_user.h

Index: ash/system/chromeos/supervised/tray_supervised_user.h
diff --git a/ash/system/chromeos/supervised/tray_supervised_user.h b/ash/system/chromeos/supervised/tray_supervised_user.h
index dbad222ea57541e8fe39de1f4b63787116142598..5d07d25feb4e5371546f4f861fb12d180bf955a6 100644
--- a/ash/system/chromeos/supervised/tray_supervised_user.h
+++ b/ash/system/chromeos/supervised/tray_supervised_user.h
@@ -15,7 +15,7 @@ class LabelTrayView;
 class SystemTray;
 
 class ASH_EXPORT TraySupervisedUser : public SystemTrayItem,
-                                          public ViewClickListener {
+                                      public ViewClickListener {
  public:
   explicit TraySupervisedUser(SystemTray* system_tray);
   virtual ~TraySupervisedUser();
@@ -43,6 +43,9 @@ class ASH_EXPORT TraySupervisedUser : public SystemTrayItem,
   // Previous login status to avoid showing notification upon unlock.
   user::LoginStatus status_;
 
+  // Previous user supervised state to avoid showing notification upon unlock.
+  bool is_user_supervised_;
+
   DISALLOW_COPY_AND_ASSIGN(TraySupervisedUser);
 };