Add the button style for combobox

ui/views/controls/combobox/combobox_menu_runner.h

+// Copyright 2013 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_COMBOBOX_COMBOBOX_MENU_RUNNER_H_
+#define UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_MENU_RUNNER_H_
+
+#include "ui/base/ui_base_types.h"
+#include "ui/views/controls/menu/menu_runner.h"
+
+namespace gfx {
+class Rect;
+}
+
+namespace views {
+
+class Combobox;
+class MenuRunner;
+
+// An interface to run a dropdown menu for a combobox.
+class ComboboxMenuRunner {

[sky, 2013/12/06 17:12:23]

I like this, but I think it should be done at the MenuRunner level. That way we
can do a similar thing for menus.

[hajimehoshi, 2013/12/09 07:44:28]

Done. (Added MenuRunnerCore to implement RunMenuAt. To be honest, I'm not
confident about the class name.)

+ public:
+  virtual ~ComboboxMenuRunner() {}
+
+  // Runs the menu for a combobox.
+  virtual MenuRunner::RunResult Run(Combobox* combobox,
+                                    MenuRunner* menu_runner,
+                                    const gfx::Rect& bounds,
+                                    ui::MenuSourceType source_type) = 0;
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_MENU_RUNNER_H_