[Background Fetch] Cleanup/fix thread safety

content/browser/storage_partition_impl.cc

Index: content/browser/storage_partition_impl.cc
diff --git a/content/browser/storage_partition_impl.cc b/content/browser/storage_partition_impl.cc
index 9bc18af4c79e096f72a4cfe37e23b4be457dec88..7efa58044ede8191f2665ad5723d36adf9a2c54c 100644
--- a/content/browser/storage_partition_impl.cc
+++ b/content/browser/storage_partition_impl.cc
@@ -417,9 +417,6 @@ StoragePartitionImpl::~StoragePartitionImpl() {
   if (GetPlatformNotificationContext())
     GetPlatformNotificationContext()->Shutdown();
 
-  if (GetBackgroundFetchContext())
-    GetBackgroundFetchContext()->Shutdown();
-
   if (GetBackgroundSyncContext())
     GetBackgroundSyncContext()->Shutdown();
 
@@ -517,8 +514,8 @@ std::unique_ptr<StoragePartitionImpl> StoragePartitionImpl::Create(
                                           partition->service_worker_context_);
   partition->platform_notification_context_->Initialize();
 
-  partition->background_fetch_context_ = new BackgroundFetchContext(
-      context, partition.get(), partition->service_worker_context_);
+  partition->background_fetch_context_ =
+      new BackgroundFetchContext(context, partition->service_worker_context_);
 
   partition->background_sync_context_ = new BackgroundSyncContext();
   partition->background_sync_context_->Init(partition->service_worker_context_);