- start Chrome OS on linux
- toggle ChromeVox on (assuming all tts bits are also in their expected places)

result:
UK voice starts speaking


expected:
en-US voice speaks.

Notes:
The UK voice is actually a downloadable voice.

What's happening is that the voices declared in the manifest are being used when ChromeVox queries for voices. This is timing related because the voices that are *actually* available need to be sent by the tts extension. However, it comes after (at times) the query from ChromeVox arrives. The UK voice is selected by tts controller and we end up with a request for it in the engine. Finally, the engine downloads the voice.
bad 

This started occurring in full once ChromeVox started respecting the system voice (and didn't set a lang) when making tts speak calls.