Fix PrintToJSONStream for oddball functions

runtime/bin/vmservice/client/lib/src/elements/vm_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 vm_view_element;
 
-import 'dart:async';
 import 'observatory_element.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
 
 @CustomTag('vm-view')
 class VMViewElement extends ObservatoryElement {
   @published VM vm;
   @published ServiceError error;
 
   VMViewElement.created() : super.created();
 
   void refresh(var done) {
     vm.reload().whenComplete(done);
   }
 }