Revert "Build Observatory with runtime"

runtime/bin/vmservice/observatory/lib/src/elements/json_view.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 json_view_element;
 
 import 'package:polymer/polymer.dart';
 import 'observatory_element.dart';
 import 'package:observatory/service.dart';
 
@@ skipping 75 matching lines @@
 class JsonViewElement extends ObservatoryElement {
   @published ServiceMap map;
   @observable String mapAsString;
   JsonViewElement.created() : super.created();
 
   void mapChanged(oldValue) {
     var jpp = new JsonPrettyPrinter();
     mapAsString = jpp.prettyPrint(map);
   }
 }