The Android voice is the one from ARC++. What callbacks are you looking for? Maybe we can plumb through those callbacks.

I'm fine with us changing the voice ordering -- "Android" is seen as a native voice on Chrome OS; perhaps move it to the end (see TtsController/TtsChromeOs under c/b/speech).

It's at least missing the word 'start' and 'word' callbacks, which STS needs to know when to draw the focus rect and word highlight.

I'll probably change the voice ordering for now, too.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4a15dd66671aa8d71fa0e95edcfb31f324623502

commit 4a15dd66671aa8d71fa0e95edcfb31f324623502
Author: Katie D <katie@chromium.org>
Date: Mon Mar 19 19:06:38 2018

Select-to-Speak should only use voices with required event types.

Some voices are missing callbacks Select-to-Speak needs. Those voices
shouldn't be displayed to the user in Select-to-Speak settings, or
available from select-to-speak at all.

Bug:  822440 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: If998f430fcc0854052b7d9bb1ed89c41b0069fb8
Reviewed-on: https://chromium-review.googlesource.com/967266
Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544093}
[modify] https://crrev.com/4a15dd66671aa8d71fa0e95edcfb31f324623502/chrome/browser/resources/chromeos/select_to_speak/select_to_speak.js
[modify] https://crrev.com/4a15dd66671aa8d71fa0e95edcfb31f324623502/chrome/browser/resources/chromeos/select_to_speak/select_to_speak_options.js