Add W3C encrypted-media tests

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

+function runTest(config,qualifier) {
+
+    var testname = testnamePrefix(qualifier, config.keysystem) + ', basic events';
+
+    var configuration = getSimpleConfigurationForContent(config.content);
+
+    if (config.initDataType && config.initData) {
+        configuration.initDataTypes = [config.initDataType];
+    }
+
+    async_test(function(test)
+    {
+        var initDataType;
+        var initData;
+        var mediaKeySession;
+
+        function onFailure(error) {
+            forceTestFailureFromPromise(test, error);
+        }
+
+        function processMessage(event)
+        {
+            assert_true(event instanceof window.MediaKeyMessageEvent);
+            assert_equals(event.target, mediaKeySession);
+            assert_equals(event.type, 'message');
+            assert_in_array(event.messageType,['license-request', 'individualization-request']);
+
+            config.messagehandler( event.messageType, event.message ).then(function(response) {
+                waitForEventAndRunStep('keystatuseschange', mediaKeySession, test.step_func(processKeyStatusesChange), test);
+                return mediaKeySession.update( response );
+            }).catch(onFailure);
+        }
+
+        function processKeyStatusesChange(event)
+        {
+            assert_true(event instanceof Event);
+            assert_equals(event.target, mediaKeySession);
+            assert_equals(event.type, 'keystatuseschange');
+            test.done();
+        }
+
+        navigator.requestMediaKeySystemAccess(config.keysystem,[configuration]).then(function(access) {
+            initDataType = access.getConfiguration().initDataTypes[0];
+
+            if (config.initDataType && config.initData) {
+                initData = config.initData;
+            } else {
+                initData = getInitData(config.content, initDataType);
+            }
+
+            return access.createMediaKeys();
+        }).then(test.step_func(function(mediaKeys) {
+            mediaKeySession = mediaKeys.createSession();
+            waitForEventAndRunStep('message', mediaKeySession, test.step_func(processMessage), test);
+            return mediaKeySession.generateRequest(initDataType, initData);
+        })).catch(onFailure);
+    }, testname );
+
+}