Introduced support for external services registration in the ServiceProtocol

sdk/lib/vmservice/running_isolate.dart

Index: sdk/lib/vmservice/running_isolate.dart
diff --git a/sdk/lib/vmservice/running_isolate.dart b/sdk/lib/vmservice/running_isolate.dart
index 6c24341a6401cb5c37170ae1555f59182371ed46..f93fac1a4aadc3cf734fbaac2e68421f3b756866 100644
--- a/sdk/lib/vmservice/running_isolate.dart
+++ b/sdk/lib/vmservice/running_isolate.dart
@@ -13,8 +13,10 @@ class RunningIsolate implements MessageRouter {
 
   String get serviceId => 'isolates/$portId';
 
-  Future<String> route(Message message) {
+  Future<String> routeRequest(Message message) {
     // Send message to isolate.
     return message.send(sendPort);
   }
+
+  void routeResponse(Message message) {}
 }