Add W3C encrypted-media tests

third_party/WebKit/LayoutTests/imported/wpt/encrypted-media/scripts/playback-persistent-license.js

+function runTest(config,qualifier) {
+
+    var testname = testnamePrefix(qualifier, config.keysystem)
+                                    + ', persistent-license, '
+                                    + /video\/([^;]*)/.exec(config.videoType)[1]
+                                    + 'playback';
+
+    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;
+
+        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');
+
+            assert_in_array( event.messageType, [ 'license-request', 'individualization-request' ] );
+
+            config.messagehandler(event.messageType, event.message).then( function( response ) {
+                return _mediaKeySession.update(response)
+            }).catch(onFailure);
+        }
+
+        function onEncrypted(event) {
+            assert_equals(event.target, _video);
+            assert_true(event instanceof window.MediaEncryptedEvent);
+            assert_equals(event.type, 'encrypted');
+
+            waitForEventAndRunStep('message', _mediaKeySession, onMessage, test);
+            _mediaKeySession.generateRequest(   config.initData ? config.initDataType : event.initDataType,
+                                                config.initData || event.initData ).catch(onFailure);
+        }
+
+        function onTimeupdate(event) {
+            if (_video.currentTime > (config.duration || 1)) {
+                _video.pause();
+                test.done();
+            }
+        }
+
+        function onPlaying(event) {
+            // Not using waitForEventAndRunStep() to avoid too many
+            // EVENT(onTimeUpdate) logs.
+            _video.addEventListener('timeupdate', onTimeupdate, true);
+        }
+
+        navigator.requestMediaKeySystemAccess(config.keysystem, [ configuration ]).then(function(access) {
+            return access.createMediaKeys();
+        }).then(function(mediaKeys) {
+            _mediaKeys = mediaKeys;
+            return _video.setMediaKeys(_mediaKeys);
+        }).then(function() {
+            _mediaKeySession = _mediaKeys.createSession( 'persistent-license' );
+            waitForEventAndRunStep('encrypted', _video, onEncrypted, test);
+            waitForEventAndRunStep('playing', _video, onPlaying, test);
+            return testmediasource(config);
+        }).then(function(source) {
+            _mediaSource = source;
+            _video.src = URL.createObjectURL(_mediaSource);
+            return source.done;
+        }).then(function(){
+            _video.play();
+        }).catch(onFailure);
+    }, testname);
+}