What steps will reproduce the problem?
(1) Open status tray.
(2) Mute volume.
(3) Tab to the mute button, then tab again (to the slider).

What is the expected result?
Some display of focus.

What happens instead?
There used to be a blue rect when muted or not. Now when it is not muted,
the slider circle is highlighted when focus, but there is nothing for
muted focus now.