Replace remaining shell references with service manager

services/service_manager/background/background_service_manager_main.h

Index: services/service_manager/background/background_service_manager_main.h
diff --git a/services/service_manager/background/background_shell_main.h b/services/service_manager/background/background_service_manager_main.h
similarity index 60%
rename from services/service_manager/background/background_shell_main.h
rename to services/service_manager/background/background_service_manager_main.h
index 67575a16f65770390ddf296a7f6c1936cc6a1a92..e25ef4a613dd739ffb8b6d0adbb62f9fb0a2ecc5 100644
--- a/services/service_manager/background/background_shell_main.h
+++ b/services/service_manager/background/background_service_manager_main.h
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef SERVICES_SERVICE_MANAGER_BACKGROUND_BACKGROUND_SHELL_MAIN_H_
-#define SERVICES_SERVICE_MANAGER_BACKGROUND_BACKGROUND_SHELL_MAIN_H_
+#ifndef SERVICES_SERVICE_MANAGER_BACKGROUND_BACKGROUND_SERVICE_MANAGER_MAIN_H_
+#define SERVICES_SERVICE_MANAGER_BACKGROUND_BACKGROUND_SERVICE_MANAGER_MAIN_H_
 
 // The "main" gn target supplies a file with a main() that calls to the child
 // process as necessary. For the main process this function is called.
 int MasterProcessMain(int argc, char** argv);
 
-#endif  // SERVICES_SERVICE_MANAGER_BACKGROUND_BACKGROUND_SHELL_MAIN_H_
+#endif  // SERVICES_SERVICE_MANAGER_BACKGROUND_BACKGROUND_SERVICE_MANAGER_MAIN_H_