Add shutdown notification and service refs to SyncServiceObserver.

ios/chrome/browser/ui/sync/sync_error_infobar_delegate.mm

 // Copyright 2012 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 "ios/chrome/browser/ui/sync/sync_error_infobar_delegate.h"
 
 #import <UIKit/UIKit.h>
 
 #include <utility>
 
@@ skipping 80 matching lines @@
 }
 
 bool SyncErrorInfoBarDelegate::Accept() {
   DCHECK(command_);
   UIWindow* main_window = [[UIApplication sharedApplication] keyWindow];
   DCHECK(main_window);
   [main_window chromeExecuteCommand:command_];
   return false;
 }
 
-void SyncErrorInfoBarDelegate::OnStateChanged() {
+void SyncErrorInfoBarDelegate::OnStateChanged(syncer::SyncService* sync) {
   // If the inforbar is in the process of being removed, nothing must be done.
   infobars::InfoBar* infobar = this->infobar();
   if (!infobar)
     return;
   SyncSetupService* sync_setup_service =
       SyncSetupServiceFactory::GetForBrowserState(browser_state_);
   SyncSetupService::SyncServiceState new_error_state =
       sync_setup_service->GetSyncServiceState();
   if (error_state_ == new_error_state)
     return;
   error_state_ = new_error_state;
   if (ios_internal::sync::IsTransientSyncError(new_error_state)) {
     infobar->RemoveSelf();
   } else {
     infobars::InfoBarManager* infobar_manager = infobar->owner();
     if (infobar_manager) {
       std::unique_ptr<ConfirmInfoBarDelegate> new_infobar_delegate(
           new SyncErrorInfoBarDelegate(browser_state_));
       infobar_manager->ReplaceInfoBar(infobar,
                                       infobar_manager->CreateConfirmInfoBar(
                                           std::move(new_infobar_delegate)));
     }
   }
 }