Added comments wrt lb/subchannel args ownership.
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 466a0fd..5af484e 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -466,6 +466,8 @@
     }
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
+    /* server_name will be copied as part of the subchannel creation. This makes
+     * the copying of args->server_name (a borrowed pointer) OK. */
     sc_args.server_name = args->server_name;
     sc_args.addr =
         (struct sockaddr *)(&args->addresses->addresses[i].address.addr);