It is time.

ui/views/controls/table/table_grouper.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_VIEWS_CONTROLS_TABLE_TABLE_GROUPER_H_
-#define UI_VIEWS_CONTROLS_TABLE_TABLE_GROUPER_H_
-
-#include "ui/views/views_export.h"
-
-namespace views {
-
-struct VIEWS_EXPORT GroupRange {
-  int start;
-  int length;
-};
-
-// TableGrouper is used by TableView to group a set of rows and treat them
-// as one. Rows that fall in the same group are selected together and sorted
-// together.
-class VIEWS_EXPORT TableGrouper {
- public:
-  virtual void GetGroupRange(int model_index, GroupRange* range) = 0;
-
- protected:
-  virtual ~TableGrouper() {}
-};
-
-}
-
-#endif  // UI_VIEWS_CONTROLS_TABLE_GROUP_TABLE_VIEW_H_