This tests the events created by WebKitMediaKeys.

RUN(mediaKeys = new WebKitMediaKeys("com.webcore.mock"))
RUN(mediaKeySession = mediaKeys.createSession("video/mock", initData))
EVENT(webkitkeymessage)
RUN(mediaKeySession.update(invalidKey))
EVENT(webkitkeyerror)
RUN(mediaKeySession.update(validKey))
EVENT(webkitkeyadded)
END OF TEST