[Background Fetch] Cleanup/fix thread safety

content/browser/storage_partition_impl.cc

 // Copyright (c) 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 "content/browser/storage_partition_impl.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <vector>
@@ skipping 399 matching lines @@
 
   if (GetServiceWorkerContext())
     GetServiceWorkerContext()->Shutdown();
 
   if (GetCacheStorageContext())
     GetCacheStorageContext()->Shutdown();
 
   if (GetPlatformNotificationContext())
     GetPlatformNotificationContext()->Shutdown();
 
-  if (GetBackgroundFetchContext())
-    GetBackgroundFetchContext()->Shutdown();
-
   if (GetBackgroundSyncContext())
     GetBackgroundSyncContext()->Shutdown();
 
   if (GetPaymentAppContext())
     GetPaymentAppContext()->Shutdown();
 }
 
 // static
 std::unique_ptr<StoragePartitionImpl> StoragePartitionImpl::Create(
     BrowserContext* context,
@@ skipping 557 matching lines @@
   media_url_request_context_ = media_url_request_context;
 }
 
 void StoragePartitionImpl::GetQuotaSettings(
     storage::OptionalQuotaSettingsCallback callback) {
   GetContentClient()->browser()->GetQuotaSettings(browser_context_, this,
                                                   std::move(callback));
 }
 
 }  // namespace content