Add some DVLOG's in MetadataDatabase::Update* methods

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 2a54d85096cc801025fb42f71bab58a5e56d4091..8a9fae6cbc4907a599eda804d8f108a9aaa85a42 100644
--- a/chrome/browser/sync_file_system/drive_backend/metadata_database.h
+++ b/chrome/browser/sync_file_system/drive_backend/metadata_database.h
@@ -231,9 +231,6 @@ class MetadataDatabase {
                                  FileTracker* tracker,
                                  base::FilePath* path) const;
 
-  void UpdateByFileMetadata(scoped_ptr<FileMetadata> file,
-                            leveldb::WriteBatch* batch);
-
   // Updates database by |changes|.
   // Marks each tracker for modified file as dirty and adds new trackers if
   // needed.
@@ -385,6 +382,10 @@ class MetadataDatabase {
   bool HasActiveTrackerForPath(int64 parent_tracker,
                                const std::string& title) const;
 
+  void UpdateByFileMetadata(const tracked_objects::Location& from_where,
+                            scoped_ptr<FileMetadata> file,
+                            leveldb::WriteBatch* batch);
+
   void WriteToDatabase(scoped_ptr<leveldb::WriteBatch> batch,
                        const SyncStatusCallback& callback);