Test multiple fake devices for audio testing selenium

[Soh]

Currently we are testing output audio sound with webrtc/selenium using the flags:

--use-fake-ui-for-media-stream 

--use-file-for-fake-audio-capture

--use-fake-device-for-media-stream

This tests fine.  My question is if it is possible and how to test a device change with these flags?  Sound currently works with our default output device during tests, but does not work with either of our alternative "fake audio output 1" and 2.