FileSystem: Prevent iterator from being deleted after database.

storage/browser/fileapi/sandbox_directory_database.h

Index: storage/browser/fileapi/sandbox_directory_database.h
diff --git a/storage/browser/fileapi/sandbox_directory_database.h b/storage/browser/fileapi/sandbox_directory_database.h
index f63b68473cdd65f298630c2b82aca5162c45d716..4899f933c44761eec3c99bb225f450d439bef7bc 100644
--- a/storage/browser/fileapi/sandbox_directory_database.h
+++ b/storage/browser/fileapi/sandbox_directory_database.h
@@ -123,6 +123,8 @@ class STORAGE_EXPORT SandboxDirectoryDatabase {
   bool AddFileInfoHelper(
       const FileInfo& info, FileId file_id, leveldb::WriteBatch* batch);
   bool RemoveFileInfoHelper(FileId file_id, leveldb::WriteBatch* batch);
+  // Close the database. Before this, all iterators associated with the database
+  // must be deleted.
   void HandleError(const tracked_objects::Location& from_here,
                    const leveldb::Status& status);