Bug 1508824 - SharedWorker.onconnect event should be a MessageEvent with an empty string as data, r=asuth

dom/workers/WorkerPrivate.cpp

@@ -4957,6 +4957,7 @@ WorkerPrivate::ConnectMessagePort(JSContext* aCx,
   }
 
   RootedDictionary<MessageEventInit> init(aCx);
+  init.mData = JS_GetEmptyStringValue(aCx);
   init.mBubbles = false;
   init.mCancelable = false;
   init.mSource.SetValue().SetAsMessagePort() = port;

testing/web-platform/meta/workers/constructors/SharedWorker/connect-event.html.ini

@@ -1,4 +0,0 @@
-[connect-event.html]
-  [connect event]
-    expected: FAIL
-