Service isolate rework

runtime/bin/vmservice/server.dart

Index: runtime/bin/vmservice/server.dart
diff --git a/runtime/bin/vmservice/server.dart b/runtime/bin/vmservice/server.dart
index c21f2426fed405accbad4a9cba38077e331711f7..17512580d5e0738c717910b532109fa75c9b51c8 100644
--- a/runtime/bin/vmservice/server.dart
+++ b/runtime/bin/vmservice/server.dart
@@ -165,15 +165,17 @@ class Server {
     return HttpServer.bind(_ip, _port).then((s) {
       _server = s;
       _server.listen(_requestHandler);
+      var ip = _server.address.address.toString();
       if (_displayMessages) {
-        var ip = _server.address.address.toString();
         var port = _server.port.toString();
         print('Observatory listening on http://$ip:$port');
       }
       // Server is up and running.
+      _notifyServerState(ip, _server.port);
       return this;
     }).catchError((e, st) {
       print('Could not start Observatory HTTP server:\n$e\n$st\n');
+      _notifyServerState("", 0);
       return this;
     });
   }
@@ -195,12 +197,17 @@ class Server {
         print('Observatory no longer listening on http://$ip:$port');
       }
       _server = null;
+      _notifyServerState("", 0);
       return this;
     }).catchError((e, st) {
       _server = null;
       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";