Add RegisterService, split out of Connect().

services/service_manager/service_manager.cc

Index: services/service_manager/service_manager.cc
diff --git a/services/service_manager/service_manager.cc b/services/service_manager/service_manager.cc
index acfcaaf51e02febad62ea28dac2cf44aa890440b..59844a4d150b590c9c2fc4df812364f496894231 100644
--- a/services/service_manager/service_manager.cc
+++ b/services/service_manager/service_manager.cc
@@ -234,6 +234,18 @@ class ServiceManager::Instance
   };
 
   // mojom::Connector implementation:
+  void RegisterService(
+      const Identity& target,
+      mojom::ClientProcessConnectionPtr client_process_connection) override {
+    Connect(
+        target,
+        mojom::InterfaceProviderRequest(),
+        std::move(client_process_connection),
+        base::Bind(
+            &service_manager::ServiceManager::Instance::EmptyConnectCallback,
+            weak_factory_.GetWeakPtr()));
+  }
+
   void Connect(const service_manager::Identity& in_target,
                mojom::InterfaceProviderRequest remote_interfaces,
                mojom::ClientProcessConnectionPtr client_process_connection,
@@ -432,6 +444,9 @@ class ServiceManager::Instance
       OnServiceLost(service_manager_->GetWeakPtr());
   }
 
+  void EmptyConnectCallback(mojom::ConnectResult result,
+                            const std::string& user_id) {}
+
   service_manager::ServiceManager* const service_manager_;
 
   // An id that identifies this instance. Distinct from pid, as a single process
@@ -884,10 +899,12 @@ void ServiceManager::OnGotResolvedName(std::unique_ptr<ConnectParams> params,
     // is already holding a corresponding ServiceRequest.
     instance->StartWithService(std::move(service));
   } else if (!client_process_connection.is_null()) {
-    // Likewise if a ClientProcessConnection was given via Connect(), it
-    // provides the Service proxy to use.
+    // This branch should be reachable only via a call to RegisterService(). We
+    // start the instance but return early before we connect to it. Clients will
+    // call Connect() with the target identity subsequently.
     instance->StartWithClientProcessConnection(
         std::move(client_process_connection));
+    return;
   } else {
     // Otherwise we create a new Service pipe.
     mojom::ServiceRequest request(&service);