views: Move combobox directory to ui/views/controls/.

views/controls/combobox/combobox_listener.h

-// Copyright (c) 2011 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 VIEWS_CONTROLS_COMBOBOX_COMBOBOX_LISTENER_H_
-#define VIEWS_CONTROLS_COMBOBOX_COMBOBOX_LISTENER_H_
-#pragma once
-
-namespace views {
-
-class Combobox;
-
-// An interface implemented by an object to let it know that the selected item
-// of a combobox changed.
-class ComboboxListener {
- public:
-  // This is invoked once the selected item changed.
-  virtual void ItemChanged(Combobox* combo_box,
-                           int prev_index,
-                           int new_index) = 0;
-
- protected:
-  virtual ~ComboboxListener() {}
-};
-
-}  // namespace views
-
-#endif  // VIEWS_CONTROLS_COMBOBOX_COMBOBOX_LISTENER_H_