[SyncFS] Add completion callback to PromoteDemotedChanges (1/3)

chrome/browser/sync_file_system/local/local_file_sync_context.h

Index: chrome/browser/sync_file_system/local/local_file_sync_context.h
diff --git a/chrome/browser/sync_file_system/local/local_file_sync_context.h b/chrome/browser/sync_file_system/local/local_file_sync_context.h
index 0decd08b2c5573a808e7c21cc055f679ca0745c5..ce47b4728bab22e76baae01c24237eab1d206a1f 100644
--- a/chrome/browser/sync_file_system/local/local_file_sync_context.h
+++ b/chrome/browser/sync_file_system/local/local_file_sync_context.h
@@ -189,8 +189,10 @@ class LocalFileSyncContext
       const HasPendingLocalChangeCallback& callback);
 
   void PromoteDemotedChanges(const GURL& origin,
-                             fileapi::FileSystemContext* file_system_context);
-  void UpdateChangesForOrigin(const GURL& origin);
+                             fileapi::FileSystemContext* file_system_context,
+                             const base::Closure& callback);
+  void UpdateChangesForOrigin(const GURL& origin,
+                              const base::Closure& callback);
 
   // They must be called on UI thread.
   void AddOriginChangeObserver(LocalOriginChangeObserver* observer);
@@ -227,13 +229,14 @@ class LocalFileSyncContext
   // Starts a timer to eventually call NotifyAvailableChangesOnIOThread.
   // The caller is expected to update origins_with_pending_changes_ before
   // calling this.
-  void ScheduleNotifyChangesUpdatedOnIOThread();
+  void ScheduleNotifyChangesUpdatedOnIOThread(const base::Closure& callback);
 
   // Called by the internal timer on IO thread to notify changes to UI thread.
-  void NotifyAvailableChangesOnIOThread();
+  void NotifyAvailableChangesOnIOThread(const base::Closure& callback);
 
   // Called from NotifyAvailableChangesOnIOThread.
-  void NotifyAvailableChanges(const std::set<GURL>& origins);
+  void NotifyAvailableChanges(const std::set<GURL>& origins,
+                              const base::Closure& callback);
 
   // Helper routines for MaybeInitializeFileSystemContext.
   void InitializeFileSystemContextOnIOThread(