Dart: Use a RawReceivePort to receive events for Mojo handles.

services/dart/test/pingpong_target/lib/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 'package:mojo/application.dart';
 import 'package:mojo/bindings.dart';
 import 'package:mojo/core.dart';
 
@@ skipping 10 matching lines @@
 
   void setClient(ProxyBase proxyBase) {
     assert(_pingPongClient == null);
     _pingPongClient = proxyBase;
   }
 
   void ping(int pingValue) => _pingPongClient.ptr.pong(pingValue + 1);
 
   // These methods are unimplemented; they merely throw on invocation.
   Future<PingPongServicePingTargetUrlResponseParams> pingTargetUrl(
-          String url, int count, [Function responseFactory]) =>
+          String url, int count,
+          [Function responseFactory]) =>
       throw "Unimplemented";
   Future<PingPongServicePingTargetServiceResponseParams> pingTargetService(
-          Object service, int count, [Function responseFactory]) =>
+          Object service, int count,
+          [Function responseFactory]) =>
       throw "Unimplemented";
   void getPingPongService(Object service) => throw "Unimplemented";
 
   void quit() {
     if (_pingPongClient != null) {
       _pingPongClient.close();
       _pingPongClient = null;
     }
     _stub.close();
   }
 }
 
 class PingPongApplication extends Application {
   PingPongApplication.fromHandle(MojoHandle handle) : super.fromHandle(handle);
 
   @override
   void acceptConnection(String requestorUrl, String resolvedUrl,
       ApplicationConnection connection) {
     connection.provideService(PingPongServiceName,
         (endpoint) => new PingPongServiceImpl(this, endpoint));
     // Close the application when the first connection goes down.
-    connection.onError = closeApplication;
+    connection.onError = ((_) => closeApplication());
   }
 
   Future closeApplication() async {
     await close();
     MojoHandle.reportLeakedHandles();
   }
 }
 
 main(List args) {
   MojoHandle appHandle = new MojoHandle(args[0]);
   String url = args[1];
   new PingPongApplication.fromHandle(appHandle);
 }