Add LogoutConfirmationController to show LogoutConfirmationDialogs

ash/system/logout_button/logout_button_tray.h

Index: ash/system/logout_button/logout_button_tray.h
diff --git a/ash/system/logout_button/logout_button_tray.h b/ash/system/logout_button/logout_button_tray.h
index 5755835b68bd7ea676a8c433ccaf11013f7fc1f0..9e1ec37aaa17d1b9d3428d3d6c5008ded862187a 100644
--- a/ash/system/logout_button/logout_button_tray.h
+++ b/ash/system/logout_button/logout_button_tray.h
@@ -7,12 +7,10 @@
 
 #include "ash/ash_export.h"
 #include "ash/system/logout_button/logout_button_observer.h"
-#include "ash/system/logout_button/logout_confirmation_dialog_view.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "ash/system/user/login_status.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "ui/views/controls/button/button.h"
 
@@ -51,31 +49,14 @@ class ASH_EXPORT LogoutButtonTray : public TrayBackgroundView,
 
   void UpdateAfterLoginStatusChange(user::LoginStatus login_status);
 
-  // Nullify the pointer to confirmation dialog, this is expected to be called
-  // when the confirmation dialog is going to be destroyed.
-  // Note: the confirmation dialog is not owned by LogoutButtonTray.
-  void ReleaseConfirmationDialog();
-
-  void SetDelegateForTest(
-      scoped_ptr<LogoutConfirmationDialogView::Delegate> delegate);
-
  private:
-  friend class LogoutConfirmationDialogTest;
-
-  bool IsConfirmationDialogShowing() const;
-  void EnsureConfirmationDialogIsShowing();
-  void EnsureConfirmationDialogIsClosed();
-
   void UpdateVisibility();
 
-  views::LabelButton* button_;  // Not owned.
+  views::LabelButton* button_;
   user::LoginStatus login_status_;
   bool show_logout_button_in_tray_;
   base::TimeDelta dialog_duration_;
 
-  LogoutConfirmationDialogView* confirmation_dialog_;  // Not owned.
-  scoped_ptr<LogoutConfirmationDialogView::Delegate> confirmation_delegate_;
-
   DISALLOW_COPY_AND_ASSIGN(LogoutButtonTray);
 };