Build Observatory as part of runtime

runtime/bin/vmservice/observatory/test/echo_test.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 'package:observatory/service_io.dart';
-import 'package:unittest/unittest.dart';
-import 'test_helper.dart';
-
-var tests = [
-
-(Isolate isolate) =>
-  isolate.vm.get('_echo').then((result) {
-    expect(result['type'], equals("message"));
-    expect(result['id'], equals("_echo"));
-    expect(result.owner, equals(isolate.vm));
-}),
-
-(Isolate isolate) =>
-  isolate.get('_echo').then((result) {
-    expect(result['type'], equals("message"));
-    expect(result['id'], equals("_echo"));
-    expect(result.owner, equals(isolate));
-}),
-
-(Isolate isolate) {
-  Completer completer = new Completer();
-  isolate.vm.events.stream.listen((ServiceEvent event) {
-    if (event.eventType == '_Echo') {
-      expect(event.data.lengthInBytes, equals(3));
-      expect(event.data.getUint8(0), equals(0));
-      expect(event.data.getUint8(1), equals(128));
-      expect(event.data.getUint8(2), equals(255));
-      completer.complete();
-    }
-  });
-  isolate.get('_echo/event');
-  return completer.future;
-},
-
-];
-
-main(args) => runIsolateTests(args, tests);