It is time.

ui/views/examples/combobox_example.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_EXAMPLES_COMBOBOX_EXAMPLE_H_
-#define UI_VIEWS_EXAMPLES_COMBOBOX_EXAMPLE_H_
-
-#include "base/macros.h"
-#include "ui/base/models/combobox_model.h"
-#include "ui/views/controls/combobox/combobox_listener.h"
-#include "ui/views/examples/example_base.h"
-
-namespace views {
-namespace examples {
-
-// A combobox model implementation that generates a list of "Item <index>".
-class VIEWS_EXAMPLES_EXPORT ComboboxModelExample : public ui::ComboboxModel {
- public:
-  ComboboxModelExample();
-  virtual ~ComboboxModelExample();
-
-  // ui::ComboboxModel:
-  virtual int GetItemCount() const override;
-  virtual base::string16 GetItemAt(int index) override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ComboboxModelExample);
-};
-
-class VIEWS_EXAMPLES_EXPORT ComboboxExample : public ExampleBase,
-                                              public ComboboxListener {
- public:
-  ComboboxExample();
-  virtual ~ComboboxExample();
-
-  // ExampleBase:
-  virtual void CreateExampleView(View* container) override;
-
- private:
-  // ComboboxListener:
-  virtual void OnPerformAction(Combobox* combobox) override;
-
-  ComboboxModelExample combobox_model_;
-  Combobox* combobox_;
-
-  DISALLOW_COPY_AND_ASSIGN(ComboboxExample);
-};
-
-}  // namespace examples
-}  // namespace views
-
-#endif  // UI_VIEWS_EXAMPLES_COMBOBOX_EXAMPLE_H_