Remove unused "sync_promo.error_message" preference

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 86bec746f3729ee4b04a2be4aa2fb073f4ac6db9..96c8035565211c4afb63f62924fc3bdd818730ec 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -233,10 +233,6 @@ enum MigratedPreferences {
 const char kBackupPref[] = "backup";
 
 #if !defined(OS_ANDROID)
-// The sync promo error message preference has been removed; this pref will
-// be cleared from user data.
-const char kSyncPromoErrorMessage[] = "sync_promo.error_message";
-
 // The AutomaticProfileResetter service used this preference to save that the
 // profile reset prompt had already been shown, however, the preference has been
 // renamed in Local State. We keep the name here for now so that we can clear
@@ -534,12 +530,6 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
       kBackupPref,
       new base::DictionaryValue(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-#if !defined(OS_ANDROID)
-  registry->RegisterStringPref(
-      kSyncPromoErrorMessage,
-      std::string(),
-      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
-#endif
 }
 
 void RegisterUserProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
@@ -569,9 +559,6 @@ void MigrateUserPrefs(Profile* profile) {
   prefs->ClearPref(kBackupPref);
 
 #if !defined(OS_ANDROID)
-  // Cleanup now-removed sync promo error message preference.
-  // TODO(fdoray): Remove this when it's safe to do so (crbug.com/268442).
-  prefs->ClearPref(kSyncPromoErrorMessage);
   // Migrate kNetworkPredictionEnabled to kNetworkPredictionOptions when not on
   // Android.  On Android, platform-specific code performs preference migration.
   // TODO(bnc): https://crbug.com/401970  Remove migration code one year after