[sync] Remove SyncService::StopAndClear() call only reachable in tests

Details below.
https://crbug.com/40797392#comment14
https://crbug.com/40797392#comment18

After this CL there is still one StopAndClear() call outside of
SyncServiceImpl but it happens in the chrome://sync-internals page [1].
I'll remove it in next CLs and make the method private.

[1] https://source.chromium.org/chromium/chromium/src/+/main:chrome/browser/ui/webui/sync_internals/sync_internals_message_handler.cc;l=296;drc=25049133043552fee361754702d705e94da850e1

Bug: 40797392
Change-Id: I7ba6fb1c6c551deaffbeadeeaed1e62707b026d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5797212
Auto-Submit: Victor Vianna <victorvianna@google.com>
Commit-Queue: Marc Treib <treib@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1343576}
diff --git a/chrome/browser/profiles/delete_profile_helper.cc b/chrome/browser/profiles/delete_profile_helper.cc
index b7a1bf0..bfe3498 100644
--- a/chrome/browser/profiles/delete_profile_helper.cc
+++ b/chrome/browser/profiles/delete_profile_helper.cc
@@ -85,17 +85,7 @@
 #if BUILDFLAG(IS_CHROMEOS_ASH)
   // On ChromeOS Ash, profile deletion uses a different codepath but some
   // browser tests do exercise this code.
-  CHECK_IS_TEST(base::NotFatalUntil::M127);
-
-  // This is believed to be unreachable (outside tests) but the stakes are quite
-  // high too, so fall back to the legacy logic just in case.
-  // TODO(crbug.com/40797392): Remove this code and replace it all with
-  // CHECK_IS_TEST() or NOTREACHED().
-  if (SyncServiceFactory::HasSyncService(profile)) {
-    syncer::SyncService* sync_service =
-        SyncServiceFactory::GetForProfile(profile);
-    sync_service->StopAndClear();
-  }
+  CHECK_IS_TEST();
 #else   // BUILDFLAG(IS_CHROMEOS_ASH)
   identity_manager->GetPrimaryAccountMutator()->ClearPrimaryAccount(
       signin_metrics::ProfileSignout::kSignoutDuringProfileDeletion);