pkg: Eliminate flaky analysis test failure.

pkg/analysis_server/test/analysis/notification_implemented_test.dart

 // Copyright (c) 2014, 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 test.analysis.notification.implemented;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/protocol.dart';
@@ skipping 294 matching lines @@
     await prepareImplementedElements();
     assertHasImplementedMember('f(_) {} // A');
   }
 
   Future waitForImplementedElements() {
     Future waitForNotification(int times) {
       if (times == 0 || implementedClasses != null) {
         return new Future.value();
       }
       return new Future.delayed(
-          Duration.ZERO, () => waitForNotification(times - 1));
+          new Duration(milliseconds:1), () => waitForNotification(times - 1));
     }
-    return waitForNotification(100);
+    return waitForNotification(30000);
   }
 }