[SmartLock] Remove Smart Lock HaTS

The HaTS survey for Smart Lock hasn't been used in a long time; let's go
ahead and remove the dead code.

TEST=Manual testing for Smart Lock.

Fixed: b/309703990
Change-Id: I6aaf3a840f95b37370baba312082ed62ae9a5dc5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5288125
Reviewed-by: Renato Silva <[email protected]>
Reviewed-by: Kyle Horimoto <[email protected]>
Reviewed-by: Gabriel Charette <[email protected]>
Reviewed-by: Ian Barkley-Yeung <[email protected]>
Commit-Queue: Curt Clemens <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1263016}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 2ab6e76..058feb1 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -996,6 +996,17 @@
 // Deprecated 02/2024
 constexpr char kSearchEnginesChoiceProfile[] = "search_engines.choice_profile";
 
+// Deprecated 02/2024.
+#if BUILDFLAG(IS_CHROMEOS_ASH)
+constexpr char kHatsUnlockSurveyCycleEndTs[] =
+    "hats_unlock_cycle_end_timestamp";
+constexpr char kHatsUnlockDeviceIsSelected[] = "hats_unlock_device_is_selected";
+constexpr char kHatsSmartLockSurveyCycleEndTs[] =
+    "hats_smartlock_cycle_end_timestamp";
+constexpr char kHatsSmartLockDeviceIsSelected[] =
+    "hats_smartlock_device_is_selected";
+#endif  // BUILDFLAG(IS_CHROMEOS_ASH)
+
 // Register local state used only for migration (clearing or moving to a new
 // key).
 void RegisterLocalStatePrefsForMigration(PrefRegistrySimple* registry) {
@@ -1401,6 +1412,14 @@
     registry->RegisterIntegerPref(pref, -1);
   }
 #endif
+
+  // Deprecated 02/2024.
+#if BUILDFLAG(IS_CHROMEOS_ASH)
+  registry->RegisterInt64Pref(kHatsSmartLockSurveyCycleEndTs, 0);
+  registry->RegisterBooleanPref(kHatsSmartLockDeviceIsSelected, false);
+  registry->RegisterInt64Pref(kHatsUnlockSurveyCycleEndTs, 0);
+  registry->RegisterBooleanPref(kHatsUnlockDeviceIsSelected, false);
+#endif
 }
 
 void ClearSyncRequestedPrefAndMaybeMigrate(PrefService* profile_prefs) {
@@ -2659,6 +2678,14 @@
   }
 #endif
 
+  // Deprecated 02/2024.
+#if BUILDFLAG(IS_CHROMEOS_ASH)
+  profile_prefs->ClearPref(kHatsSmartLockSurveyCycleEndTs);
+  profile_prefs->ClearPref(kHatsSmartLockDeviceIsSelected);
+  profile_prefs->ClearPref(kHatsUnlockSurveyCycleEndTs);
+  profile_prefs->ClearPref(kHatsUnlockDeviceIsSelected);
+#endif
+
   // Please don't delete the following line. It is used by PRESUBMIT.py.
   // END_MIGRATE_OBSOLETE_PROFILE_PREFS