Fired when the media track's active quality changes.
Fired when a quality of the track becomes unavailable.
- A Quality can become unavailable due to a DRM restriction (e.g. HDCP).
Fired when the media track's target quality changes.
Fired when the track updates.
- A track might update because a change propagated from a remote player (e.g. Chromecast).
The events fired by a MediaTrack.