mash: Move system tray cast code into //ash/common

ash/system/chromeos/screen_security/screen_capture_tray_item.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 ASH_SYSTEM_CHROMEOS_SCREEN_CAPTURE_SCREEN_CAPTURE_TRAY_ITEM_H_
-#define ASH_SYSTEM_CHROMEOS_SCREEN_CAPTURE_SCREEN_CAPTURE_TRAY_ITEM_H_
-
-#include "ash/common/shell_observer.h"
-#include "ash/common/system/chromeos/screen_security/screen_capture_observer.h"
-#include "ash/system/chromeos/screen_security/screen_tray_item.h"
-#include "base/macros.h"
-
-namespace views {
-class View;
-}
-
-namespace ash {
-
-class ASH_EXPORT ScreenCaptureTrayItem : public ScreenTrayItem,
-                                         public ScreenCaptureObserver,
-                                         public ShellObserver {
- public:
-  explicit ScreenCaptureTrayItem(SystemTray* system_tray);
-  ~ScreenCaptureTrayItem() override;
-
- private:
-  // Overridden from SystemTrayItem.
-  views::View* CreateTrayView(LoginStatus status) override;
-  views::View* CreateDefaultView(LoginStatus status) override;
-
-  // Overridden from ScreenTrayItem.
-  void CreateOrUpdateNotification() override;
-  std::string GetNotificationId() override;
-
-  // Overridden from ScreenCaptureObserver.
-  void OnScreenCaptureStart(
-      const base::Closure& stop_callback,
-      const base::string16& screen_capture_status) override;
-  void OnScreenCaptureStop() override;
-
-  // Overridden from ShellObserver.
-  void OnCastingSessionStartedOrStopped(bool started) override;
-
-  base::string16 screen_capture_status_;
-  bool is_casting_ = false;
-
-  DISALLOW_COPY_AND_ASSIGN(ScreenCaptureTrayItem);
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_CHROMEOS_SCREEN_CAPTURE_SCREEN_CAPTURE_TRAY_ITEM_H_