Start the migration of passwords from the Keychain.

components/password_manager/core/browser/password_manager.cc

Index: components/password_manager/core/browser/password_manager.cc
diff --git a/components/password_manager/core/browser/password_manager.cc b/components/password_manager/core/browser/password_manager.cc
index fb8178bc02c49ada89127b90f3aa58ee54d92117..d4e09d8ebeed9bb80bb3ff5a32c5d0f67f869645 100644
--- a/components/password_manager/core/browser/password_manager.cc
+++ b/components/password_manager/core/browser/password_manager.cc
@@ -17,6 +17,7 @@
 #include "components/autofill/core/common/password_form_field_prediction_map.h"
 #include "components/password_manager/core/browser/affiliation_utils.h"
 #include "components/password_manager/core/browser/browser_save_password_progress_logger.h"
+#include "components/password_manager/core/browser/keychain_migration_status_mac.h"
 #include "components/password_manager/core/browser/password_autofill_manager.h"
 #include "components/password_manager/core/browser/password_form_manager.h"
 #include "components/password_manager/core/browser/password_manager_client.h"
@@ -142,6 +143,10 @@ void PasswordManager::RegisterProfilePrefs(
   registry->RegisterBooleanPref(prefs::kPasswordManagerAllowShowPasswords,
                                 true);
   registry->RegisterListPref(prefs::kPasswordManagerGroupsForDomains);
+#if defined(OS_MACOSX)
+  registry->RegisterIntegerPref(prefs::kKeychainMigrationStatus,
+                                static_cast<int>(MigrationStatus::NOT_STARTED));
+#endif
 }
 
 #if defined(OS_WIN)