Chrome Version: 71.0.3578.94 (Official Build) (64-bit)
Chrome OS Version: 11151.59.0 (Official Build) stable-channel nocturne
Chrome OS Platform: Pixel Slate

Steps To Reproduce:
(1) Sign in to multiple accounts
(2) Visit music.google.com from one account and play music
(3) Switch to the other account
(4) Press the play/pause button on an attached pair of headphones

Expected Result:
Music is paused.

Actual Result:
Music will not pause.

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)
Always

What is the impact to the user, and is there a workaround? If so, what is
it?
Switching to the account that's playing music, hitting Pause, and switching back works as expected.