I'm writing about an issue that occurs with VoiceOver and Chrome in Revision History mode in Docs. When arrowing through the revisions in the Revision History sidebar, nothing is being verbalized. However, these verbalizations are happening in other screen reader and browser combinations due to us setting the aria-activedescendant property on an outer div with role="listbox".

I've boiled the issue down to a minimal repro case here.
https://ldaquila.users.x20web.corp.google.com/www/activedescendant.html
 In this example, every five seconds, the div with role="listbox" has its aria-activedescendant property toggled between "Option 1" and "Option 2". Other screen readers will verbalize these aria-activedescendant property changes, but the Chrome and VoiceOver combination does not.

Do you know whether Chrome is firing the right events to update VoiceOver in this repro case?