Dart: Adds a content handler and a test.

services/dart/lib/src/application.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.
+
+part of application;
+
+// The Application interface doesn't explicitly have a Shell as a Client, but
+// that is what is at the other end of the MessagePipe.
+abstract class Application extends application.ApplicationInterface
+                           with shell.ShellCalls {
+  List<service_provider.ServiceProviderClient> _clients;
+
+  Application(core.MojoMessagePipeEndpoint endpoint) :
+      _clients = [],
+      super(endpoint);
+
+  Application.fromHandle(core.MojoHandle shellHandle) :
+      _clients = [],
+      super.fromHandle(shellHandle);
+
+  Function interfaceFactoryClosure() => (endpoint) => null;
+
+  void initialize(List<String> args) {
+  }
+
+  void acceptConnection(
+      String requestorUrl,
+      service_provider.ServiceProviderInterface services,
+      service_provider.ServiceProviderClient exposedServices) {
+    var closure = interfaceFactoryClosure();
+    if (closure != null) {
+      var serviceProvider = new ServiceProvider(closure);
+      services.delegate = serviceProvider;
+      services.listen();
+    }
+  }
+
+  core.MojoMessagePipeEndpoint connectToService(String url, String service) {
+    var applicationPipe = new core.MojoMessagePipe();
+    var clientEndpoint = applicationPipe.endpoints[0];
+    var applicationEndpoint = applicationPipe.endpoints[1];
+    var serviceProviderClient =
+        new service_provider.ServiceProviderClient.unbound();
+    callConnectToApplication(url, serviceProviderClient, null);
+    serviceProviderClient.callConnectToService(service, applicationEndpoint);
+    _clients.add(serviceProviderClient);
+    return clientEndpoint;
+  }
+
+  void close() {
+    _clients.forEach((c) => c.close());
+    _clients.clear();
+    super.close();
+  }
+}