
This is a fallout from some changes in MessageTray.Source, which now requires either defining the iconName/iconType properties on it, or implementing createNotificationIcon, and we're not doing any of those. Fix it by storing the gicon of the source object and using a helper method to create the icon actor on demand, to avoid any case when the same actor might be added twice to different containers. https://bugzilla.gnome.org/show_bug.cgi?id=678428