Dart: Adds optional named arguments for creating bindings.

services/dart/test/pingpong/main.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:services/dart/test/pingpong_service.mojom.dart';
 
 class PingPongClientImpl implements PingPongClient {
   final PingPongClientStub stub;
   Completer _completer;
   int _count;
 
   PingPongClientImpl.unbound(this._count, this._completer)
       : stub = new PingPongClientStub.unbound() {
-    stub.delegate = this;
+    stub.impl = this;
   }
 
   void pong(int pongValue) {
     if (pongValue == _count) {
       _completer.complete(null);
       stub.close();
     }
   }
 }
 
 class PingPongServiceImpl implements PingPongService {
   PingPongServiceStub _stub;
   Application _application;
   PingPongClientProxy _pingPongClient;
 
   PingPongServiceImpl(Application application, MojoMessagePipeEndpoint endpoint)
       : _application = application {
-    _stub = new PingPongServiceStub.fromEndpoint(endpoint)
-            ..delegate = this
-            ..listen();
+    _stub = new PingPongServiceStub.fromEndpoint(endpoint, impl: this);
   }
 
   PingPongServiceImpl.fromStub(this._stub) {
-    _stub.delegate = this;
+    _stub.impl = this;
   }
 
   listen() => _stub.listen();
 
   void setClient(ProxyBase proxyBase) {
-    assert(_pingPongClient== null);
+    assert(_pingPongClient == null);
     _pingPongClient = proxyBase;
   }
 
   void ping(int pingValue) {
     if (_pingPongClient != null) {
       _pingPongClient.ptr.pong(pingValue + 1);
     }
   }
 
   Future pingTargetUrl(String url, int count, Function responseFactory) async {
     if (_application == null) {
       return responseFactory(false);
     }
     var completer = new Completer();
-    var pingPongService= new PingPongServiceProxy.unbound();
+    var pingPongService = new PingPongServiceProxy.unbound();
     _application.connectToService(url, pingPongService);
 
     var pingPongClient = new PingPongClientImpl.unbound(count, completer);
     pingPongService.ptr.setClient(pingPongClient.stub);
     pingPongClient.stub.listen();
 
     for (var i = 0; i < count; i++) {
       pingPongService.ptr.ping(i);
     }
     await completer.future;
     pingPongService.ptr.quit();
+    pingPongService.close();
 
     return responseFactory(true);
   }
 
-  Future pingTargetService(ProxyBase proxyBase,
-                           int count,
-                           Function responseFactory) async {
+  Future pingTargetService(ProxyBase proxyBase, int count,
+      Function responseFactory) async {
     var pingPongService = proxyBase;
     var completer = new Completer();
     var client = new PingPongClientImpl.unbound(count, completer);
     pingPongService.ptr.setClient(client.stub);
     client.stub.listen();
 
     for (var i = 0; i < count; i++) {
       pingPongService.ptr.ping(i);
     }
     await completer.future;
     pingPongService.ptr.quit();
+    pingPongService.close();
 
     return responseFactory(true);
   }
 
   getPingPongService(PingPongServiceStub serviceStub) {
     new PingPongServiceImpl.fromStub(serviceStub)..listen();
   }
 
   void quit() {
     if (_pingPongClient != null) {
       _pingPongClient.close();
       _pingPongClient = null;
     }
     _stub.close();
-    if (_application != null) {
-      _application.close();
-    }
+    _stub = null;
   }
 }
 
 class PingPongApplication extends Application {
   PingPongApplication.fromHandle(MojoHandle handle) : super.fromHandle(handle);
 
   @override
   void acceptConnection(String requestorUrl, String resolvedUrl,
-                        ApplicationConnection connection) {
-    connection.provideService(PingPongServiceName,
+      ApplicationConnection connection) {
+    connection.provideService(
+        PingPongServiceName,
         (endpoint) => new PingPongServiceImpl(this, endpoint));
     connection.listen();
   }
 }
 
 main(List args) {
   MojoHandle appHandle = new MojoHandle(args[0]);
   String url = args[1];
   new PingPongApplication.fromHandle(appHandle);
 }