Add LogoutConfirmationController to show LogoutConfirmationDialogs

ash/system/session/logout_confirmation_controller.h

Index: ash/system/session/logout_confirmation_controller.h
diff --git a/ash/system/session/logout_confirmation_controller.h b/ash/system/session/logout_confirmation_controller.h
new file mode 100644
index 0000000000000000000000000000000000000000..1b91d4d81ceba84ed15f87c4e3aa805ad36eb4ea
--- /dev/null
+++ b/ash/system/session/logout_confirmation_controller.h
@@ -0,0 +1,69 @@
+// 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_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
+#define ASH_SYSTEM_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
+
+#include "ash/ash_export.h"
+#include "ash/shell_observer.h"
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+
+namespace base {
+class TickClock;
+}
+
+namespace ash {
+namespace internal {
+
+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 {
+ public:
+  // The |logout_closure| must be safe to call as long as |this| is alive.
+  explicit LogoutConfirmationController(const base::Closure& logout_closure);
+  virtual ~LogoutConfirmationController();
+
+  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(scoped_ptr<base::TickClock> clock);
+
+  // ShellObserver:
+  virtual 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();
+
+ private:
+  scoped_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 internal
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_