Introduced support for external services registration in the ServiceProtocol

runtime/observatory/lib/src/models/objects/event.dart

 // Copyright (c) 2016, 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 models;
 
 abstract class Event {
   /// The timestamp (in milliseconds since the epoch) associated with this
   /// event. For some isolate pause events, the timestamp is from when the
   /// isolate was paused. For other events, the timestamp is from when the
@@ skipping 179 matching lines @@
 
 bool isAtAsyncSuspension(DebugEvent event) {
   if (event is PauseBreakpointEvent) {
     return event.atAsyncSuspension;
   }
   if (event is PauseInterruptedEvent) {
     return event.atAsyncSuspension;
   }
   return false;
 }
+
+abstract class ServiceEvent extends Event {
+  /// The identifier of the service
+  String get service;
+
+  /// The JSON-RPC 2.0 Method that identifes this instance
+  String get method;
+}
+
+abstract class ServiceRegisteredEvent extends ServiceEvent {
+  /// The alias associated with this new instance
+  String get alias;
+}
+
+abstract class ServiceUnregisteredEvent extends ServiceEvent {}