Testing the TracksSupport behavior with audio tracks.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


The tracks button should be disabled initially as we wait for metadata and audio tracks to be added.
PASS mediaController.controls.tracksButton.enabled is false

Eventually the audio tracks will be added and the tracks button will be enabled.
PASS mediaController.controls.tracksButton.enabled became true

PASS successfullyParsed is true

TEST COMPLETE