[SyncFS] Add browser_tests to test authentication state of SyncFS

chrome/browser/sync_file_system/sync_file_system_service.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_SYNC_FILE_SYSTEM_SERVICE_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_SYNC_FILE_SYSTEM_SERVICE_H_
 
 #include <map>
 #include <string>
 
@@ skipping 70 matching lines @@
   void OnPromotionCompleted(int* num_running_jobs);
   void CheckIfIdle();
 
   TaskLogger* task_logger() { return &task_logger_; }
 
   void CallOnIdleForTesting(const base::Closure& callback);
 
  private:
   friend class SyncFileSystemServiceFactory;
   friend class SyncFileSystemServiceTest;
+  friend class SyncFileSystemTest;
   friend struct base::DefaultDeleter<SyncFileSystemService>;
   friend class LocalSyncRunner;
   friend class RemoteSyncRunner;
 
   explicit SyncFileSystemService(Profile* profile);
   virtual ~SyncFileSystemService();
 
   void Initialize(scoped_ptr<LocalFileSyncService> local_file_service,
                   scoped_ptr<RemoteFileSyncService> remote_file_service);
 
@@ skipping 85 matching lines @@
 
   bool promoting_demoted_changes_;
   base::Closure idle_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncFileSystemService);
 };
 
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_SYNC_FILE_SYSTEM_SERVICE_H_