[Chrome OS MD] Draw a 1px separator between 2 tray items

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"
 #include "ash/common/system/tray/tray_background_view.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "ui/views/controls/button/button.h"
 
 namespace views {
 class LabelButton;
 }
 
 namespace ash {
+class ViewObserver;
 
 // Adds a logout button to the launcher's status area if enabled by the
 // kShowLogoutButtonInTray pref.
 class ASH_EXPORT LogoutButtonTray : public TrayBackgroundView,
                                     public LogoutButtonObserver,
                                     public views::ButtonListener {
  public:
-  explicit LogoutButtonTray(WmShelf* wm_shelf);
+  explicit LogoutButtonTray(WmShelf* wm_shelf, ViewObserver* view_observer);
   ~LogoutButtonTray() override;
 
   // TrayBackgroundView:
   void SetShelfAlignment(ShelfAlignment alignment) override;
   base::string16 GetAccessibleNameForTray() override;
   void HideBubbleWithView(const views::TrayBubbleView* bubble_view) override;
   void ClickedOutsideBubble() override;
 
   // LogoutButtonObserver:
   void OnShowLogoutButtonInTrayChanged(bool show) override;
@@ skipping 11 matching lines @@
   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_