Chrome Version: 71.0.3560.0 Canary
OS: Mac OS X 10.13

What steps will reproduce the problem?
(1)  Enable Mirroring Service and Views Cast Dialog: --enable-features=AudioServiceAudioStreams,NetworkService,MirroringService,ViewsCastDialog 
(2) Go to https://vimeo.com/channels/staffpicks/290539530
(3) Mirror tab to a Cast device
(4) Fullscreen video and trigger media remoting
(5) Some time later, stop remoting by clicking the 'X' in the Cast dialog

What is the expected result?
After #4, the dialog says "Casting media (vimeo.com)" underneath the target device
After #5, video playback resumes without an error message

What happens instead?
After #4, the dialog says "Casting tab (vimeo.com)"
After #5, an error appears over the video: "Video playback error, switched to mirroring"