Replace deprecated base::NonThreadSafe in components/signin in favor of SequenceChecker.

components/signin/core/browser/account_tracker_service.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/signin/core/browser/account_tracker_service.h"
 
 #include <stddef.h>
 
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 42 matching lines @@
 
 // This must be a string which can never be a valid domain.
 const char AccountTrackerService::kNoHostedDomainFound[] = "NO_HOSTED_DOMAIN";
 
 // This must be a string which can never be a valid picture URL.
 const char AccountTrackerService::kNoPictureURLFound[] = "NO_PICTURE_URL";
 
 AccountTrackerService::AccountTrackerService() : signin_client_(nullptr) {}
 
 AccountTrackerService::~AccountTrackerService() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 }
 
 // static
 void AccountTrackerService::RegisterPrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterListPref(AccountTrackerService::kAccountInfoPref);
   registry->RegisterIntegerPref(prefs::kAccountIdMigrationState,
                                 AccountTrackerService::MIGRATION_NOT_STARTED);
 }
 
@@ skipping 429 matching lines @@
       NotifyAccountUpdated(state);
 
     SaveToPrefs(state);
   }
   return info.account_id;
 }
 
 void AccountTrackerService::RemoveAccount(const std::string& account_id) {
   StopTrackingAccount(account_id);
 }