Chrome Version: 69.0.3493.0
OS: 10.13.6

What steps will reproduce the problem?
(1) Click Cast icon in toolbar, click Sources, pick Desktop
(2) Cast Mac desktop to a Cast device
(3) Note that an issue appears next to the sink "Casting system audio is not supported on this device"
(4) Click Stop and leave dialog open, note that sink reverts to Available

What is the expected result?

Issue bubble disappears when route is terminated

What happens instead?

Issue bubble lingers for 10-15 seconds, then disappears

Per discussion with takumif@, issues are associated with sinks.  Some issues may only make sense while a route is active and we could:
- MR clear these issues when the route is terminated
- pass a flag that so the UI can clear these issues when the sink is available