updateVoices method
Called by an engine to update its list of voices. This list overrides any
voices declared in this extension's manifest.
voices
Array of tts.TtsVoice objects representing the available
voices for speech synthesis.
Implementation
void updateVoices(List<TtsVoice> voices) {
$js.chrome.ttsEngine.updateVoices(voices.toJSArray((e) => e.toJS));
}