Signin screen and locked screen status area focus advancing

ash/common/system/tray/system_tray_notifier.h

Index: ash/common/system/tray/system_tray_notifier.h
diff --git a/ash/common/system/tray/system_tray_notifier.h b/ash/common/system/tray/system_tray_notifier.h
index 29bb9f521061c39977d5f613cee9636c32ef3d10..84417b0006f421bb092ef6358aa8b9fa44c9bc72 100644
--- a/ash/common/system/tray/system_tray_notifier.h
+++ b/ash/common/system/tray/system_tray_notifier.h
@@ -24,6 +24,7 @@ class AccessibilityObserver;
 class AudioObserver;
 class ClockObserver;
 class IMEObserver;
+class StatusAreaFocusObserver;
 struct UpdateInfo;
 class UpdateObserver;
 class UserObserver;
@@ -86,6 +87,11 @@ class ASH_EXPORT SystemTrayNotifier {
                            const std::string& from_locale,
                            const std::string& to_locale);
 
+  // Status area focus.
+  void AddStatusAreaFocusObserver(StatusAreaFocusObserver* observer);
+  void RemoveStatusAreaFocusObserver(StatusAreaFocusObserver* observer);
+  void NotifyWillReturnFocusToWebContents(bool reverse);
+
   // OS updates.
   void AddUpdateObserver(UpdateObserver* observer);
   void RemoveUpdateObserver(UpdateObserver* observer);
@@ -174,6 +180,7 @@ class ASH_EXPORT SystemTrayNotifier {
   base::ObserverList<ClockObserver> clock_observers_;
   base::ObserverList<IMEObserver> ime_observers_;
   base::ObserverList<LocaleObserver> locale_observers_;
+  base::ObserverList<StatusAreaFocusObserver> status_area_focus_observers_;
   base::ObserverList<UpdateObserver> update_observers_;
   base::ObserverList<UserObserver> user_observers_;