Dart: Removes need to call listen().

services/dart/dart_apptests/pingpong_apptests.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'dart:async';
 import 'mojo:application';
 import 'mojo:bindings';
 import 'mojo:core';
 
 import 'package:apptest/apptest.dart';
@@ skipping 21 matching lines @@
 pingpongApptests(Application application) {
   group('Ping-Pong Service Apptests', () {
     // Verify that "pingpong.dart" implements the PingPongService interface
     // and sends responses to our client.
     test('Ping Service To Pong Client', () async {
       var pingPongServiceProxy = new PingPongServiceProxy.unbound();
       application.connectToService("mojo:dart_pingpong", pingPongServiceProxy);
 
       var pingPongClient = new _TestingPingPongClient.unbound();
       pingPongServiceProxy.ptr.setClient(pingPongClient.stub);
-      pingPongClient.stub.listen();
 
       pingPongServiceProxy.ptr.ping(1);
       var pongValue = await pingPongClient.waitForPong();
       expect(pongValue, equals(2));
 
       pingPongServiceProxy.ptr.ping(100);
       pongValue = await pingPongClient.waitForPong();
       expect(pongValue, equals(101));
 
       pingPongClient.stub.close();
@@ skipping 40 matching lines @@
     // Verify that Dart can implement an interface "request" parameter.
     test('Get Target Service', () async {
       var pingPongServiceProxy = new PingPongServiceProxy.unbound();
       application.connectToService("mojo:dart_pingpong", pingPongServiceProxy);
 
       var targetServiceProxy = new PingPongServiceProxy.unbound();
       pingPongServiceProxy.ptr.getPingPongService(targetServiceProxy);
 
       var pingPongClient = new _TestingPingPongClient.unbound();
       targetServiceProxy.ptr.setClient(pingPongClient.stub);
-      pingPongClient.stub.listen();
 
       targetServiceProxy.ptr.ping(1);
       var pongValue = await pingPongClient.waitForPong();
       expect(pongValue, equals(2));
 
       targetServiceProxy.ptr.ping(100);
       pongValue = await pingPongClient.waitForPong();
       expect(pongValue, equals(101));
 
       pingPongClient.stub.close();
       targetServiceProxy.close();
       pingPongServiceProxy.close();
     });
   });
 }