Remove calls to [new Future] work around issue 11911.

sdk/lib/_internal/pub/test/error_group_test.dart

Index: sdk/lib/_internal/pub/test/error_group_test.dart
diff --git a/sdk/lib/_internal/pub/test/error_group_test.dart b/sdk/lib/_internal/pub/test/error_group_test.dart
index a5433bdd4d5e9aa43659c0fa3e92237e53020b77..331a1ffd92bebf907458735045105f4fc28fc3a4 100644
--- a/sdk/lib/_internal/pub/test/error_group_test.dart
+++ b/sdk/lib/_internal/pub/test/error_group_test.dart
@@ -247,7 +247,7 @@ main() {
       expect(stream.first, throwsFormatException);
       errorGroup.signalError(new FormatException());
 
-      expect(new Future(() {
+      expect(newFuture(() {
         controller.add('value');
       }), completes);
     });