Add RegisterService, split out of Connect().

services/service_manager/public/interfaces/connector.mojom

Index: services/service_manager/public/interfaces/connector.mojom
diff --git a/services/service_manager/public/interfaces/connector.mojom b/services/service_manager/public/interfaces/connector.mojom
index b1e7314c42fb14e423764fc9201257ec8c2b4001..51356a0a1089ecc4943816cc007038f7598f4779 100644
--- a/services/service_manager/public/interfaces/connector.mojom
+++ b/services/service_manager/public/interfaces/connector.mojom
@@ -87,6 +87,11 @@ struct ClientProcessConnection {
 
 // Encapsulates establishing connections with other Services.
 interface Connector {
+  // Registers a Service in a process started by someone other than the Service
+  // Manager.
+  RegisterService(Identity name,

[Ken Rockot(use gerrit already), 2017/01/05 20:31:48]

nit: I think RegisterInstance might be a more accurate name

+                  ClientProcessConnection client_process_connection);

[Ken Rockot(use gerrit already), 2017/01/05 20:31:48]

nit: Maybe just flatten service and pid_receiver_request into the args here?
Also you could use a PIDReceiver& instead of a raw pipe handle.

+
   // Requests a connection with another service. The service originating the
   // request is referred to as the "source" and the one receiving the "target".
   //