Dart: Futures -> Callbacks.

mojo/dart/apptests/test_apps/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 15 matching lines @@
   }
 
   void setClient(PingPongClientInterface client) {
     assert(_pingPongClient == null);
     _pingPongClient = client;
   }
 
   void ping(int pingValue) => _pingPongClient.pong(pingValue + 1);
 
   // These methods are unimplemented; they merely throw on invocation.
-  dynamic pingTargetUrl(String url, int count, [Function responseFactory]) =>
+  void pingTargetUrl(String url, int count, void callback(bool ok)) =>
       throw "Unimplemented";
-  dynamic pingTargetService(PingPongServiceInterface service, int count,
-      [Function responseFactory]) =>
+  void pingTargetService(PingPongServiceInterface service, int count,
+      void callback(bool ok)) =>
       throw "Unimplemented";
-  dynamic getPingPongServiceDelayed(PingPongServiceInterfaceRequest service,
-      [Function responseFactory]) =>
+  void getPingPongServiceDelayed(PingPongServiceInterfaceRequest service) =>
       throw "Unimplemented";
 
   void getPingPongService(PingPongServiceInterfaceRequest service) {
     new PingPongServiceImpl.fromInterfaceRequest(service);
   }
 
   void quit() {}
 }
 
 class PingPongApplication extends Application {
@@ skipping 10 matching lines @@
   Future closeApplication() async {
     await close();
     MojoHandle.reportLeakedHandles();
   }
 }
 
 main(List args, Object handleToken) {
   MojoHandle appHandle = new MojoHandle(handleToken);
   new PingPongApplication.fromHandle(appHandle);
 }