Build Observatory with runtime

runtime/observatory/lib/src/elements/io_view.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.
 
 library io_view_element;
 
 import 'dart:async';
 import 'observatory_element.dart';
 import 'service_ref.dart';
 import 'package:observatory/service.dart';
@@ skipping 263 matching lines @@
 
   @override
   void detached() {
     super.detached();
     if (_updateTimer != null) {
       _updateTimer.cancel();
       _updateTimer = null;
     }
   }
 }