[SyncFS] Add RemoteToLocalSyncer skeleton

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 dced9760c5afcab2562ce6bf4b3ed19bfdb433fa..b032eeb14f7313ebe5aa410fe62109e7d7e528d7 100644
--- a/chrome/browser/sync_file_system/drive_backend/metadata_database.h
+++ b/chrome/browser/sync_file_system/drive_backend/metadata_database.h
@@ -224,6 +224,17 @@ class MetadataDatabase {
                      const FileDetails& updated_details,
                      const SyncStatusCallback& callback);
 
+  // Returns true if there is a normal priority dirty tracker.
+  // Assigns the dirty tracker if exists and |tracker| is non-NULL.
+  bool GetNormalPriorityDirtyTracker(FileTracker* tracker);
+
+  // Returns true if there is a low priority dirty tracker.
+  // Assigns the dirty tracker if exists and |tracker| is non-NULL.
+  bool GetLowPriorityDirtyTracker(FileTracker* tracker);
+
+  void ResolveTrivialDirtiness(int64 tracker_id,

[kinuko, 2013/11/05 13:36:13]

Can you add a comment? What's the definition of 'trivial' here?

[tzik, 2013/11/06 04:56:08]

Hm, let me move this to RemoteToLocalSyncer, and rename it to
OfflineSolvableDirtiness.

+                               const SyncStatusCallback& callback);
+  
  private:
   friend class ListChangesTaskTest;
   friend class MetadataDatabaseTest;