Add the streamListen and streamCancel rpcs to the vm service.

runtime/vm/service/message.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.
 
 part of vmservice;
 
 class Message {
   final Completer _completer = new Completer.sync();
   bool get completed => _completer.isCompleted;
   /// Future of response.
   Future<String> get response => _completer.future;
+  Client client;
 
   // Client-side identifier for this message.
   final serial;
 
   // In new messages.
   final String method;
 
   // In old messages.
   final List path = new List();
 
   final Map params = new Map();
 
   void _setPath(List<String> pathSegments) {
     if (pathSegments == null) {
       return;
     }
     pathSegments.forEach((String segment) {
       if (segment == null || segment == '') {
         return;
       }
       path.add(segment);
     });
   }
 
-  Message.fromJsonRpc(Map map)
+  Message.fromJsonRpc(this.client, Map map)
       : serial = map['id'], method = map['method'] {
     params.addAll(map['params']);
   }
 
   static String _methodNameFromUri(Uri uri) {
     if (uri == null) {
       return '';
     }
     if (uri.pathSegments.length == 0) {
       return '';
     }
     return uri.pathSegments[0];
   }
 
-  Message.fromUri(Uri uri)
+  Message.fromUri(this.client, Uri uri)
       : method = _methodNameFromUri(uri) {
     params.addAll(uri.queryParameters);
   }
 
-  Message.forIsolate(Uri uri, RunningIsolate isolate)
+  Message.forIsolate(this.client, Uri uri, RunningIsolate isolate)
       : method = _methodNameFromUri(uri) {
     params.addAll(uri.queryParameters);
     params['isolateId'] = isolate.serviceId;
   }
 
   Uri toUri() {
     return new Uri(path: method, queryParameters: params);
   }
 
   dynamic toJson() {
@@ skipping 85 matching lines @@
     };
     _completer.complete(JSON.encode(response));
   }
 }
 
 bool sendIsolateServiceMessage(SendPort sp, List m)
     native "VMService_SendIsolateServiceMessage";
 
 void sendRootServiceMessage(List m)
     native "VMService_SendRootServiceMessage";