Migrated http_server_idle_timeout_test from the SDK. (#34)

diff --git a/test/http_server_idle_timeout_test.dart b/test/http_server_idle_timeout_test.dart
new file mode 100644
index 0000000..2f03bb9
--- /dev/null
+++ b/test/http_server_idle_timeout_test.dart
@@ -0,0 +1,55 @@
+// Copyright (c) 2018, 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.
+
+import "dart:async";
+import 'dart:io' show Socket;
+
+import 'package:http_io/http_io.dart';
+import 'package:test/test.dart';
+
+Future<Null> testTimeoutAfterRequest() {
+  final completer = new Completer<Null>();
+  HttpServer.bind("127.0.0.1", 0).then((server) {
+    server.idleTimeout = null;
+
+    server.listen((request) {
+      server.idleTimeout = const Duration(milliseconds: 100);
+      request.response.close();
+    });
+
+    Socket.connect("127.0.0.1", server.port).then((socket) {
+      var data = "GET / HTTP/1.1\r\nContent-Length: 0\r\n\r\n";
+      socket.write(data);
+      socket.listen(null, onDone: () {
+        socket.close();
+        server.close();
+        completer.complete();
+      });
+    });
+  });
+  return completer.future;
+}
+
+Future<Null> testTimeoutBeforeRequest() {
+  final completer = new Completer<Null>();
+  HttpServer.bind("127.0.0.1", 0).then((server) {
+    server.idleTimeout = const Duration(milliseconds: 100);
+
+    server.listen((request) => request.response.close());
+
+    Socket.connect("127.0.0.1", server.port).then((socket) {
+      socket.listen(null, onDone: () {
+        socket.close();
+        server.close();
+        completer.complete();
+      });
+    });
+  });
+  return completer.future;
+}
+
+void main() {
+  test('timeoutAfterRequest', () => testTimeoutAfterRequest());
+  test('timeoutBeforeRequest', () => testTimeoutBeforeRequest());
+}