Better CrOS logout button for vertical trays.

ash/common/system/chromeos/session/logout_button_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_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_TRAY_H_
 #define ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_TRAY_H_
 
 #include "ash/ash_export.h"
 #include "ash/common/login_status.h"
 #include "ash/common/system/chromeos/session/logout_button_observer.h"
@@ skipping 27 matching lines @@
   void OnShowLogoutButtonInTrayChanged(bool show) override;
   void OnLogoutDialogDurationChanged(base::TimeDelta duration) override;
 
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
   void UpdateAfterLoginStatusChange(LoginStatus login_status);
 
  private:
   void UpdateVisibility();
+  void UpdateButtonTextAndImage(LoginStatus login_status,
+                                ShelfAlignment alignment);
 
   views::LabelButton* button_;
   LoginStatus login_status_;
   bool show_logout_button_in_tray_;
   base::TimeDelta dialog_duration_;
 
   DISALLOW_COPY_AND_ASSIGN(LogoutButtonTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_TRAY_H_