// https://w3c.github.io/mediacapture-main/#mediadevices
[Exposed=Window, SecureContext]
interface MediaDevices : EventTarget {
    attribute EventHandler ondevicechange;
    Promise<sequence<MediaDeviceInfo>> enumerateDevices();
    // https://w3c.github.io/mediacapture-main/#dom-mediadevices-getsupportedconstraints
    // Returns a dictionary whose members are the constrainable properties known to the User Agent.
    MediaTrackSupportedConstraints getSupportedConstraints();
    Promise<MediaStream> getUserMedia(optional MediaStreamConstraints constraints = {});
};