Fixes for Blink roll.

tests/html/worker_test.dart

Index: tests/html/worker_test.dart
diff --git a/tests/html/worker_test.dart b/tests/html/worker_test.dart
index 81b8558d96aa035981f8808555b03dcbcb3ec47d..d24394bb74d8c23bad1353aa2ca4b8330739c620 100644
--- a/tests/html/worker_test.dart
+++ b/tests/html/worker_test.dart
@@ -37,9 +37,10 @@ main() {
       var blob = new Blob([workerScript], 'text/javascript');
       var url = Url.createObjectUrl(blob);
       var worker = new Worker(url);
-      return worker.onMessage.first.then((e) {
+      var test = expectAsync1((e) {
         expect(e.data, 'WorkerMessage');
       });
+      worker.onMessage.first.then(test);
     });
   });
 }