Fix http_close_test to wait for server close.

tests/standalone/io/http_close_test.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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import "dart:async";
@@ skipping 52 matching lines @@
       client.get("localhost", server.port, "/")
           .then((request) => request.close())
           .then((response) => check());
     }
   });
 }
 
 
 void testClientCloseDelayed(int connections) {
   HttpServer.bind().then((server) {
+    int closed = 0;
+    void check() {
+      closed++;
+      // Wait for both server and client to see the connections as closed.
+      if (closed == connections * 2) {
+        Expect.equals(0, server.connectionsInfo().active);
+        Expect.equals(server.connectionsInfo().total,
+                      server.connectionsInfo().idle);
+        server.close();
+      }
+    }
     server.listen((request) {
-      request.pipe(request.response);
+      request.pipe(request.response)
+          .then((_) => check());
     });
-    int closed = 0;
     var client = new HttpClient();
     for (int i = 0; i < connections; i++) {
       var req;
       client.post("localhost", server.port, "/")
           .then((request) {
             req = request;
             request.add(new Uint8List(1024));
             return request.response;
           })
           .then((response) {
             req.close();
             // Ensure we don't accept the response until we have send the entire
             // request.
             response.listen(
                 (_) {},
                 onDone: () {
-                  closed++;
-                  if (closed == connections) {
-                    Expect.equals(0, server.connectionsInfo().active);
-                    Expect.equals(server.connectionsInfo().total,
-                                  server.connectionsInfo().idle);
-                    server.close();
-                  }
+                  check();
                 });
           });
     }
   });
 }
 
 
 void main() {
   testClientAndServerCloseNoListen(10);
   testClientCloseServerListen(10);
   testClientCloseDelayed(10);
 }