Dart: Simplifies the handle watcher. Various cleanups and bugfixes.

mojo/dart/test/bindings_generation_test.dart

 // Copyright 2014 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 'dart:isolate';
 import 'dart:mojo_bindings' as bindings;
 import 'dart:mojo_core' as core;
 import 'dart:typed_data';
 
 import 'package:mojo/dart/testing/expect.dart';
 import 'package:mojo/public/interfaces/bindings/tests/sample_interfaces.mojom.dart' as sample;
 
 
 class ProviderImpl extends sample.ProviderInterface {
   ProviderImpl(core.MojoMessagePipeEndpoint endpoint) : super(endpoint);
 
   echoString(String a) {
     var response = new sample.Provider_EchoString_ResponseParams();
     response.a = a;
-    return response;
+    return new Future.value(response);
   }
 
   echoStrings(String a, String b) {
     var response = new sample.Provider_EchoStrings_ResponseParams();
     response.a = a;
     response.b = b;
-    return response;
+    return new Future.value(response);
   }
 
   echoMessagePipeHanlde(core.RawMojoHandle a) {
     var response = new sample.Provider_EchoMessagePipeHandle_ResponseParams();
     response.a = a;
-    return response;
+    return new Future.value(response);
   }
 
   echoEnum(int a) {
     var response = new sample.Provider_EchoEnum_ResponseParams();
     response.a = a;
-    return response;
+    return new Future.value(response);
   }
 }
 
 
 void providerIsolate(core.MojoMessagePipeEndpoint endpoint) {
   var provider = new ProviderImpl(endpoint);
   provider.listen();
 }
 
 
@@ skipping 32 matching lines @@
   Expect.equals("mojo!", echoStringsResponse.b);
 
   client.close();
 }
 
 
 main() async {
   await test();
   await testAwait();
 }