[SyncFS] Add idle callback to SyncFileSystemService for testing

chrome/browser/sync_file_system/sync_file_system_service.h

Index: chrome/browser/sync_file_system/sync_file_system_service.h
diff --git a/chrome/browser/sync_file_system/sync_file_system_service.h b/chrome/browser/sync_file_system/sync_file_system_service.h
index 32b9dc5c945b9b91d487e6f719d97ee5a6fb6eeb..53d3cd506b48de72cede46811adbefcf9b1d227a 100644
--- a/chrome/browser/sync_file_system/sync_file_system_service.h
+++ b/chrome/browser/sync_file_system/sync_file_system_service.h
@@ -80,8 +80,13 @@ class SyncFileSystemService
   virtual SyncServiceState GetSyncServiceState() OVERRIDE;
   virtual SyncFileSystemService* GetSyncService() OVERRIDE;
 
+  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;
@@ -182,6 +187,9 @@ class SyncFileSystemService
   TaskLogger task_logger_;
   ObserverList<SyncEventObserver> observers_;
 
+  bool promoting_demoted_changes_;
+  base::Closure idle_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(SyncFileSystemService);
 };