mash: Convert virtual keyboard system tray item to wm common types

ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.h

-// Copyright 2014 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 ASH_SYSTEM_CHROMEOS_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_TRAY_H_
-#define ASH_SYSTEM_CHROMEOS_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_TRAY_H_
-
-#include "ash/common/keyboard/keyboard_ui_observer.h"
-#include "ash/common/system/tray/tray_background_view.h"
-#include "base/macros.h"
-#include "ui/views/controls/button/button.h"
-
-namespace views {
-class ImageButton;
-}
-
-namespace ash {
-
-// TODO(sky): make this visible on non-chromeos platforms.
-class VirtualKeyboardTray : public TrayBackgroundView,
-                            public views::ButtonListener,
-                            public KeyboardUIObserver {
- public:
-  explicit VirtualKeyboardTray(WmShelf* wm_shelf);
-  ~VirtualKeyboardTray() override;
-
-  // TrayBackgroundView:
-  void SetShelfAlignment(ShelfAlignment alignment) override;
-  base::string16 GetAccessibleNameForTray() override;
-  void HideBubbleWithView(const views::TrayBubbleView* bubble_view) override;
-  void ClickedOutsideBubble() override;
-  bool PerformAction(const ui::Event& event) override;
-
-  // views::ButtonListener:
-  void ButtonPressed(views::Button* sender, const ui::Event& event) override;
-
-  // KeyboardUIObserver:
-  void OnKeyboardEnabledStateChanged(bool new_value) override;
-
- private:
-  views::ImageButton* button_;  // Not owned.
-
-  DISALLOW_COPY_AND_ASSIGN(VirtualKeyboardTray);
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_CHROMEOS_VIRTUAL_KEYBOARD_VIRTUAL_KEYBOARD_TRAY_H_