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

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

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library error_group_test;
 
 import 'dart:async';
 
 import 'package:unittest/unittest.dart';
 
@@ skipping 229 matching lines @@
       expect(errorGroup.done, throwsFormatException);
       controller.addError(new FormatException());
     });
 
     test('should pass a signaled exception to the stream if it has a listener '
          'and should unsubscribe that stream', () {
       // errorGroup shouldn't top-level the exception
       expect(stream.first, throwsFormatException);
       errorGroup.signalError(new FormatException());
 
-      expect(new Future(() {
+      expect(newFuture(() {
         controller.add('value');
       }), completes);
     });
 
     test('should notify the error group of a signaled exception even if the '
         'stream has a listener', () {
       expect(stream.first, throwsFormatException);
       expect(errorGroup.done, throwsFormatException);
       errorGroup.signalError(new FormatException());
     });
@@ skipping 176 matching lines @@
              completion(equals(['value1', 'value2'])));
       controller..add('value1')..add('value2')..close();
 
       expect(signal.future.then((_) {
         // shouldn't cause a top-level exception
         completer.completeError(new FormatException());
       }), completes);
     });
   });
 }