2nd attempt at adding streamListen/streamCancel to the service protocol.

runtime/bin/vmservice/server.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_io;
 
 class WebSocketClient extends Client {
   static const int PARSE_ERROR_CODE = 4000;
   static const int BINARY_MESSAGE_ERROR_CODE = 4001;
   static const int NOT_MAP_ERROR_CODE = 4002;
@@ skipping 11 matching lines @@
         map = JSON.decode(message);
       } catch (e) {
         socket.close(PARSE_ERROR_CODE, 'Message parse error: $e');
         return;
       }
       if (map is! Map) {
         socket.close(NOT_MAP_ERROR_CODE, 'Message must be a JSON map.');
         return;
       }
       var serial = map['id'];
-      onMessage(serial, new Message.fromJsonRpc(map));
+      onMessage(serial, new Message.fromJsonRpc(this, map));
     } else {
       socket.close(BINARY_MESSAGE_ERROR_CODE, 'Message must be a string.');
     }
   }
 
   void post(dynamic result) {
     try {
       socket.add(result);
     } catch (_) {
       print("Ignoring error posting over WebSocket.");
@@ skipping 91 matching lines @@
       assert(resource != null);
     }
     if (resource != null) {
       // Serving up a static resource (e.g. .css, .html, .png).
       request.response.headers.contentType =
           ContentType.parse(resource.mimeType);
       request.response.add(resource.data);
       request.response.close();
       return;
     }
-    var message = new Message.fromUri(request.uri);
+    var message = new Message.fromUri(this, request.uri);
     var client = new HttpRequestClient(request, _service);
     client.onMessage(null, message);
   }
 
   Future startup() {
     if (_server != null) {
       // Already running.
       return new Future.value(this);
     }
 
@@ skipping 47 matching lines @@
       print('Could not shutdown Observatory HTTP server:\n$e\n$st\n');
       _notifyServerState("", 0);
       return this;
     });
   }
 
 }
 
 void _notifyServerState(String ip, int port)
     native "VMServiceIO_NotifyServerState";