RemoveSessionLengthLimitObserver  297 ash/system/chromeos/session/tray_session_length_limit.cc       RemoveSessionLengthLimitObserver(this);
RemoveSessionLengthLimitObserver   82 ash/system/tray/system_tray_notifier.h   void RemoveSessionLengthLimitObserver(SessionLengthLimitObserver* observer);