Show driver-transport natural types.

Update the LLCPP file selection drop-downs to also show
driver/natrual_messaging.h and driver/natrual_messaging.cc

Change-Id: I3f652ed2266a1516533ae99fa21e524bf7f4f100
Reviewed-on: https://fuchsia-review.googlesource.com/c/fidlbolt/+/678311
Reviewed-by: Mitchell Kember <mkember@google.com>
diff --git a/backend/server.go b/backend/server.go
index 1860a8c..622e159 100644
--- a/backend/server.go
+++ b/backend/server.go
@@ -287,7 +287,8 @@
 			"wire_messaging.cc", "wire_test_base.h", "natural_types.h",
 			"natural_types.cc", "fidl.h", "natural_messaging.h",
 			"natural_messaging.cc", "driver/wire.h", "driver/wire_messaging.h",
-			"driver/wire_messaging.cc":
+			"driver/wire_messaging.cc", "driver/natural_messaging.h",
+			"driver/natural_messaging.cc":
 		case "tables":
 		default:
 			return fmt.Errorf("invalid LLCPP file option: %q", r.Options.File)
@@ -529,7 +530,8 @@
 			"wire_messaging.cc", "wire_test_base.h", "natural_types.h",
 			"natural_types.cc", "fidl.h", "natural_messaging.h",
 			"natural_messaging.cc", "driver/wire.h", "driver/wire_messaging.h",
-			"driver/wire_messaging.cc":
+			"driver/wire_messaging.cc", "driver/natural_messaging.h",
+			"driver/natural_messaging.cc":
 			// TODO(fxbug.dev/85703): Sanitize paths.
 			return temp.readFile("fidl", string(analysis.root), "cpp", r.Options.File)
 		default:
diff --git a/frontend/src/elm/Mode.elm b/frontend/src/elm/Mode.elm
index 16a4c9f..6fe8d8f 100644
--- a/frontend/src/elm/Mode.elm
+++ b/frontend/src/elm/Mode.elm
@@ -240,6 +240,8 @@
                         , ( "driver/wire.h", "driver/wire.h" )
                         , ( "driver/wire_messaging.h", "driver/wire_messaging.h" )
                         , ( "driver/wire_messaging.cc", "driver/wire_messaging.cc" )
+                        , ( "driver/natural_messaging.h", "driver/natural_messaging.h" )
+                        , ( "driver/natural_messaging.cc", "driver/natural_messaging.cc" )
 
                         -- TODO(fxbug.dev/93781): For consistency, we're showing
                         -- "tables.c" in the dropdown, but still passing the