Revert "Build Observatory with runtime"

runtime/bin/vmservice/observatory/lib/src/elements/object_common.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.
 
 library object_common_element;
 
 import 'dart:async';
 import 'observatory_element.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
@@ skipping 26 matching lines @@
     return object.isolate.get(object.id + "/inbound_references?limit=$arg")
         .then((ServiceObject obj) {
            inboundReferences = obj;
         });
   }
 
   void refresh(Function onDone) {
     object.reload().whenComplete(onDone);
   }
 }