Chrome: 69.0.3464.0

Steps to repro:
# With ChromeVox running, set ChromeVox to use an Acapela voice
# With ChromeVox running and speaking with the Acapela voice, Open the Acapela extensions page
# Select remove next to the voice that ChromeVox is speaking with
# ChromeVox stops speaking immediately
# Restart ChromeVox
# ChromeVox briefly speaks with the default system voice and then goes silent
# In that brief time, you might be able to hear ChromeVox say there is an ok and cancel button
# Hit OK
# ChromeVox switches to previous default

Expected: ChromeVox should switch to previous default when the remove dialog is open

Actual: ChromeVox stops talking until the voice is actually removed