Additional cleanup of pre-md system menu user row code.

ash/BUILD.gn

Index: ash/BUILD.gn
diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index cba1cb3a34af1a6dd23970b52a7db6806550c19a..9e1f6d35fa24efe5dadda30ae2aa59e6839f5efd 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn
@@ -128,8 +128,6 @@ component("ash") {
     "common/new_window_controller.cc",
     "common/new_window_controller.h",
     "common/palette_delegate.h",
-    "common/popup_message.cc",
-    "common/popup_message.h",
     "common/scoped_root_window_for_new_windows.cc",
     "common/scoped_root_window_for_new_windows.h",
     "common/session/session_controller.cc",
@@ -1176,9 +1174,6 @@ test("ash_unittests") {
     # TODO: convert to use AshTest http://crbug.com/654492.
     "common/metrics/pointer_metrics_recorder_unittest.cc",
 
-    # TODO: convert to use AshTest http://crbug.com/654493.
-    "common/popup_message_unittest.cc",
-
     # TODO: convert to use AshTest http://crbug.com/654494.
     "common/shelf/shelf_application_menu_model_unittest.cc",
     "common/shelf/shelf_background_animator_unittest.cc",