Chrome Version: 70.0.3507.0
OS: OSX 10.13.6 (Mac only)
MR: 7018.730.0.0

What steps will reproduce the problem?
(1) Enable VoiceOver by pressing ‘command key+FN key+F5’
(2) Click Cast icon in toolbar
(3) Press tab to move through device list until the "Sources" button is highlighted. VoiceOver reads "Sources button. You are currently on a button. To click this button, press control-option-space.
(4) Press enter key.

What is the expected result? Either the sources menu should open, or nothing should happen. (Since VoiceOver does say to press control-option-space, not the enter key.) I think it's unexpected for the Cast button to be pressed since it's not highlighted.

What happens instead? The Cast button is clicked, and casting starts.


Note: Issue does not occur on CrOS or Win