BackgroundSyncManager tracks client registrations

content/browser/background_sync/background_sync_context_impl.h

 // Copyright 2015 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.
 
 #ifndef CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_CONTEXT_IMPL_H_
 #define CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_CONTEXT_IMPL_H_
 
 #include <set>
 
 #include "base/memory/ref_counted.h"
@@ skipping 31 matching lines @@
   // be deleted. Call on the IO thread.
   void ServiceHadConnectionError(BackgroundSyncServiceImpl* service);
 
   // Call on the IO thread.
   BackgroundSyncManager* background_sync_manager() const override;
 
  protected:
   ~BackgroundSyncContextImpl() override;
 
  private:
+  friend class BackgroundSyncServiceImplTest;
+
   void CreateBackgroundSyncManager(
       const scoped_refptr<ServiceWorkerContextWrapper>& context);
 
   void CreateServiceOnIOThread(
       mojo::InterfaceRequest<BackgroundSyncService> request);
 
   void ShutdownOnIO();
 
   // Only accessed on the IO thread.
   scoped_ptr<BackgroundSyncManager> background_sync_manager_;
 
   // The services are owned by this. They're either deleted
   // during ShutdownOnIO or when the channel is closed via
   // ServiceHadConnectionError. Only accessed on the IO thread.
   std::set<BackgroundSyncServiceImpl*> services_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundSyncContextImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_CONTEXT_IMPL_H_