Introduced support for external services registration in the ServiceProtocol

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

Index: runtime/observatory/lib/src/models/objects/event.dart
diff --git a/runtime/observatory/lib/src/models/objects/event.dart b/runtime/observatory/lib/src/models/objects/event.dart
index 9fd73594879cf90ea1ccad2ad583c19cd37e0204..4739554d31ee17b2e361a2850340085380ec54a3 100644
--- a/runtime/observatory/lib/src/models/objects/event.dart
+++ b/runtime/observatory/lib/src/models/objects/event.dart
@@ -197,3 +197,18 @@ bool isAtAsyncSuspension(DebugEvent event) {
   }
   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 {}