[SyncFS] Unconditionally demote remote file trackers on remote-to-local sync

chrome/browser/sync_file_system/drive_backend/metadata_database.h

Index: chrome/browser/sync_file_system/drive_backend/metadata_database.h
diff --git a/chrome/browser/sync_file_system/drive_backend/metadata_database.h b/chrome/browser/sync_file_system/drive_backend/metadata_database.h
index cfd745d94ece7a99ac2d1b8b77c8575b8fa07d33..ad72469d0a603edb6db4aa5a818e10a2e9a4a996 100644
--- a/chrome/browser/sync_file_system/drive_backend/metadata_database.h
+++ b/chrome/browser/sync_file_system/drive_backend/metadata_database.h
@@ -322,7 +322,9 @@ class MetadataDatabase {
 
   // Changes the priority of the tracker to low.
   void LowerTrackerPriority(int64 tracker_id);
-  void PromoteLowerPriorityTrackersToNormal();
+  bool PromoteLowerPriorityTrackersToNormal();
+
+  void PromoteDemotedTracker(int64 tracker_id);
 
   // Returns true if there is a normal priority dirty tracker.
   // Assigns the dirty tracker if exists and |tracker| is non-NULL.