Set the video widget for the fullscreen window
Set the video widget for the fullscreen window

Otherwise the mouse cursor won't be hidden after a timeout
and the 'Leave fullscreen' button won't dissapear when we
unfullscreen the call window.

GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets,Distrotech/telepathy-account-widgets,Distrotech/telepathy-account-widgets