Keep track of when a socket has been destroyed

pkg/scheduled_test/lib/src/scheduled_server/safe_http_server.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library safe_http_server;
 
 import 'dart:async';
 import 'dart:io';
 
 // TODO(nweiz): remove this when issue 9140 is fixed.
@@ skipping 12 matching lines @@
   static Future<SafeHttpServer> bind([String host = "localhost",
       int port = 0, int backlog = 0]) {
     return HttpServer.bind(host, port, backlog: backlog)
         .then((server) => new SafeHttpServer(server));
   }
 
   SafeHttpServer(HttpServer server)
       : super(server),
         _inner = server;
 
-  void close() => _inner.close();
+  Future close() => _inner.close();
 
   int get port => _inner.port;
 
   set sessionTimeout(int timeout) {
     _inner.sessionTimeout = timeout;
   }
 
   HttpConnectionsInfo connectionsInfo() => _inner.connectionsInfo();
 
   StreamSubscription<HttpRequest> listen(void onData(HttpRequest value),
@@ skipping 88 matching lines @@
   Future<HttpResponse> addStream(Stream<List<int>> stream) =>
     _inner.addStream(stream);
   Future close() => _inner.close();
   void write(Object obj) => _inner.write(obj);
   void writeAll(Iterable objects, [String separator = ""]) =>
     _inner.writeAll(objects, separator);
   void writeCharCode(int charCode) => _inner.writeCharCode(charCode);
   void writeln([Object obj = ""]) => _inner.writeln(obj);
   void addError(error) => _inner.addError(error);
 }