Add W3C encrypted-media tests

third_party/WebKit/LayoutTests/imported/wpt/encrypted-media/scripts/events-session-closed-event.js

+function runTest(config, qualifier)
+{
+    var testname = testnamePrefix(qualifier, config.keysystem) + ' test MediaKeySession closed event.';
+
+    var configuration = {
+        initDataTypes: [config.initDataType],
+        audioCapabilities: [{
+            contentType: config.audioType
+        }],
+        videoCapabilities: [{
+            contentType: config.videoType
+        }],
+        sessionTypes: ['temporary']
+    };
+
+    promise_test(function (test) {
+        var initDataType;
+        var initData;
+        var mediaKeySession;
+
+        return navigator.requestMediaKeySystemAccess(config.keysystem, [configuration]).then(function (access) {
+            initDataType = access.getConfiguration().initDataTypes[0];
+            return access.createMediaKeys();
+        }).then(function (mediaKeys) {
+            mediaKeySession = mediaKeys.createSession();
+            if(config.initData) {
+                initData = config.initData;
+            } else {
+                initData = stringToUint8Array(atob(config.content.keys[0].initData));
+            }
+            return mediaKeySession.generateRequest(initDataType, initData);
+        }).then(function() {
+            // close() should result in the closed promise being
+            // fulfilled.
+            return mediaKeySession.close();
+        }).then(function (result) {
+            assert_equals(result, undefined);
+            // Wait for the session to be closed.
+            return mediaKeySession.closed;
+        }).then(function (result) {
+            assert_equals(result, undefined);
+            // Now that the session is closed, verify that the
+            // closed attribute immediately returns a fulfilled
+            // promise.
+            return mediaKeySession.closed;
+        }).then(function (result) {
+            assert_equals(result, undefined);
+        }).catch(function(error) {
+            assert_unreached('Error: ' + error.name);
+        });
+    }, testname);
+}