Add Observatory test of io.

tests/standalone/io/observatory.dart

+// Copyright (c) 2014, 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:convert';
+import 'dart:io';
+import 'dart:mirrors';
+
+import 'package:expect/expect.dart';
+import 'package:async_helper/async_helper.dart';
+
+Map lookupServiceObject(String path) {
+  var io = currentMirrorSystem().findLibrary(const Symbol('dart.io'));
+  var m = MirrorSystem.getSymbol('_serviceObjectHandler', io);
+  var paths = Uri.parse(path).pathSegments;
+  Expect.equals('io', paths.first);
+  return JSON.decode(
+      io.invoke(m, [paths.sublist(1), [], []]).reflectee);
+}
+
+
+String getServicePath(obj) {
+  var io = currentMirrorSystem().findLibrary(const Symbol('dart.io'));
+  var m = MirrorSystem.getSymbol('_getServicePath', io);
+  return io.invoke(m, [obj]).reflectee;
+}
+
+
+Future testHttpServer1() {
+  return HttpServer.bind('localhost', 0).then((server) {
+    var path = getServicePath(server);
+    var map = lookupServiceObject(path);
+    Expect.equals(map['type'], 'HttpServer');
+    Expect.equals(map['id'], path);
+    Expect.equals(map['address'], 'localhost');
+    Expect.equals(map['port'], server.port);
+    Expect.equals(map['closed'], false);
+    Expect.equals(map['idle'], 0);
+    Expect.equals(map['active'], 0);
+    var socket = map['socket'];
+    Expect.equals(socket['type'], '@Socket');
+    Expect.equals(socket['kind'], 'Listening');
+    // Validate owner back-ref.
+    socket = lookupServiceObject(socket['id']);
+    Expect.equals(socket['owner']['id'], path);
+    return server.close();
+  });
+}
+
+
+void main() {
+  final tests = [
+    testHttpServer1(),
+  ];
+
+  asyncStart();
+  // Run one test at a time.
+  Future.forEach(tests, (f) => f)
+      .then((_) {
+        asyncEnd();
+      });
+}