function runTest(config,qualifier) {

    var testname = testnamePrefix(qualifier, config.keysystem)
                                    + ', persistent-license, '
                                    + /video\/([^;]*)/.exec(config.videoType)[1]
                                    + ', playback, check events';

    var configuration = {   initDataTypes: [ config.initDataType ],
                            audioCapabilities: [ { contentType: config.audioType } ],
                            videoCapabilities: [ { contentType: config.videoType } ],
                            sessionTypes: [ 'persistent-license' ] };


    async_test(function(test) {
        var _video = config.video,
            _mediaKeys,
            _mediaKeySession,
            _mediaSource,
            _receivedTimeupdateEvent = false,
            _startedReleaseSequence = false,
            _events = [ ];

        function recordEventFunc(eventType) {
            return function() { _events.push(eventType); };
        }

        function recordEventFuncAndCheckExpirationForNaN(eventType) {
            return function() {
                _events.push(eventType);
                assert_equals(_mediaKeySession.expiration, NaN);
            };
        }

        function onFailure(error) {
            forceTestFailureFromPromise(test, error);
        }

        function onMessage(event) {
            assert_equals( event.target, _mediaKeySession );
            assert_true( event instanceof window.MediaKeyMessageEvent );
            assert_equals( event.type, 'message');

            if (!_startedReleaseSequence) {
                assert_in_array(event.messageType, ['license-request', 'individualization-request']);
            } else {
                assert_equals(event.messageType, 'license-release');
            }

            if (event.messageType !== 'individualization-request') {
                _events.push(event.messageType);
            }

            config.messagehandler(event.messageType, event.message ).then(function(response) {
                _events.push(event.messageType + '-response');
                return _mediaKeySession.update(response);
            }).then(test.step_func(function() {
                _events.push(event.messageType + '-response-resolved');
                if (event.messageType === 'license-release') {
                    test.step_timeout(function() {
                        checkEventSequence(_events, [
                            'generaterequest',
                            [    // potentially repeating
                                'license-request',
                                'license-request-response',
                                'license-request-response-resolved'
                            ],
                            'keystatuseschange-usablekey',
                            'playing',
                            'remove-resolved',
                            'keystatuseschange-allkeysreleased',
                            'license-release',
                            'license-release-response',
                            'closed-attribute-resolved',
                            'license-release-response-resolved',
                            'keystatuseschange-empty'
                        ]);
                        test.done();
                    }, 100);
                }
            })).catch(onFailure);
        }

        function onKeyStatusesChange(event) {
            assert_equals(event.target, _mediaKeySession);
            assert_true(event instanceof window.Event);
            assert_equals(event.type, 'keystatuseschange');
            var hasKeys = false,
                usableKey = false;    // true if any key usable.
            _mediaKeySession.keyStatuses.forEach(function(value, keyid) {
                assert_in_array(value, ['usable', 'released']);
                hasKeys = true;
                usableKey = usableKey || (value === 'usable');
            });

            if (!hasKeys) {
                _events.push('keystatuseschange-empty');
            } else if (usableKey) {
                _events.push('keystatuseschange-usablekey');
            } else {
                _events.push('keystatuseschange-allkeysreleased');
            }
        }

        function onEncrypted(event) {
            assert_equals(event.target, _video);
            assert_true(event instanceof window.MediaEncryptedEvent);
            assert_equals(event.type, 'encrypted');

            _mediaKeySession.generateRequest(   config.initData ? config.initDataType : event.initDataType,
                                                config.initData || event.initData ).then(recordEventFunc('generaterequest')
            ).catch(onFailure);
        }

        function onTimeupdate(event) {
            if ( _video.currentTime > ( config.duration || 1 ) && !_receivedTimeupdateEvent ) {
                _receivedTimeupdateEvent = true;
                _video.pause();
                _video.removeAttribute('src');
                _video.load();

                _startedReleaseSequence = true;
                _mediaKeySession.remove()
                    .then(recordEventFuncAndCheckExpirationForNaN('remove-resolved'))
                    .catch(onFailure);
            }
        }

        function onPlaying(event) {
            _events.push( 'playing' );
        }

        navigator.requestMediaKeySystemAccess(config.keysystem, [ configuration ]).then(function(access) {
            return access.createMediaKeys();
        }).then(function(mediaKeys) {
            _mediaKeys = mediaKeys;
            return _video.setMediaKeys(_mediaKeys);
        }).then(function() {
            waitForEventAndRunStep('encrypted', _video, onEncrypted, test);
            waitForEventAndRunStep('playing', _video, onPlaying, test);
            // Not using waitForEventAndRunStep() to avoid too many
            // EVENT(onTimeUpdate) logs.
            _video.addEventListener('timeupdate', onTimeupdate, true);
            _mediaKeySession = _mediaKeys.createSession( 'persistent-license' );
            waitForEventAndRunStep('keystatuseschange', _mediaKeySession, onKeyStatusesChange, test);
            waitForEventAndRunStep('message', _mediaKeySession, onMessage, test);
            _mediaKeySession.closed
                .then(recordEventFuncAndCheckExpirationForNaN('closed-attribute-resolved'))
                .catch(onFailure);
            return testmediasource(config);
        }).then(function(source) {
            _mediaSource = source;
            _video.src = URL.createObjectURL(_mediaSource);
            return source.done;
        }).then(function(){
            _video.play();
        }).catch(onFailure);
    }, testname);
}