Definition
Encrypted Media Extensions defines MediaKeySession
[Exposed=Window, SecureContext] interface MediaKeySession : EventTarget {
readonly attribute DOMString sessionId;
readonly attribute unrestricted double expiration;
readonly attribute Promise<MediaKeySessionClosedReason> closed;
readonly attribute MediaKeyStatusMap keyStatuses;
attribute EventHandler onkeystatuseschange;
attribute EventHandler onmessage;
Promise<undefined> generateRequest (DOMString initDataType, BufferSource initData);
Promise<boolean> load (DOMString sessionId);
Promise<undefined> update (BufferSource response);
Promise<undefined> close ();
Promise<undefined> remove ();
};