Because clicking on the summary item to have it display its notification
is a more deliberate action than hovering, we can now grab focus in that
notification. This makes chat notifications in the summary more convenient
to use because you don't need to click on the text entry there.
We pop down the notification when the user clicks anywhere outside of it,
triggers the overview, or the run dialog.
https://bugzilla.gnome.org/show_bug.cgi?id=617224
46906eef43