mash: Convert system tray logout button to wm common types

ash/common/system/chromeos/session/logout_confirmation_controller.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_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
-#define ASH_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
+#ifndef ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/shell_observer.h"
+#include "ash/common/system/chromeos/session/last_window_closed_observer.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
 namespace base {
 class TickClock;
 }
 
 namespace ash {
 
 class LogoutConfirmationDialog;
 
 // This class shows a dialog asking the user to confirm or deny logout and
 // terminates the session if the user either confirms or allows the countdown
 // shown in the dialog to expire.
+//
 // It is guaranteed that no more than one confirmation dialog will be visible at
 // any given time. If there are multiple requests to show a confirmation dialog
 // at the same time, the dialog whose countdown expires first is shown.
-class ASH_EXPORT LogoutConfirmationController : public ShellObserver {
+//
+// In public sessions, asks the user to end the session when the last window is
+// closed.
+class ASH_EXPORT LogoutConfirmationController
+    : public ShellObserver,
+      public LastWindowClosedObserver {
  public:
   // The |logout_closure| must be safe to call as long as |this| is alive.
   explicit LogoutConfirmationController(const base::Closure& logout_closure);
   ~LogoutConfirmationController() override;
 
   base::TickClock* clock() const { return clock_.get(); }
 
   // Shows a LogoutConfirmationDialog. If a confirmation dialog is already being
   // shown, it is closed and a new one opened if |logout_time| is earlier than
   // the current dialog's |logout_time_|.
   void ConfirmLogout(base::TimeTicks logout_time);
 
   void SetClockForTesting(std::unique_ptr<base::TickClock> clock);
 
   // ShellObserver:
   void OnLockStateChanged(bool locked) override;
 
   // Called by the |dialog_| when the user confirms logout.
   void OnLogoutConfirmed();
 
   // Called by the |dialog_| when it is closed.
   void OnDialogClosed();
 
   LogoutConfirmationDialog* dialog_for_testing() const { return dialog_; }
 
  private:
+  // LastWindowClosedObserver:
+  void OnLastWindowClosed() override;
+
   std::unique_ptr<base::TickClock> clock_;
   base::Closure logout_closure_;
 
   base::TimeTicks logout_time_;
   LogoutConfirmationDialog* dialog_;  // Owned by the Views hierarchy.
   base::Timer logout_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(LogoutConfirmationController);
 };
 
 }  // namespace ash
 
-#endif  // ASH_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_