This is the container that contains the elements that are interesting
for keynav, so it must be aware of focus-chain and -navigation.
https://gitlab.gnome.org/GNOME/gnome-shell/issues/2210
this._otherUserButton, 'visible', Gio.SettingsBindFlags.GET);
// Main Box
- let mainBox = new Clutter.Actor();
+ let mainBox = new St.Widget();
mainBox.add_constraint(new Layout.MonitorConstraint({ primary: true }));
mainBox.add_child(this._stack);
mainBox.add_child(this._notificationsBox);