cros: Use SessionController to enable system tray settings / notifications tray

ash/system/web_notification/web_notification_tray.h

 // Copyright (c) 2012 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_WEB_NOTIFICATION_WEB_NOTIFICATION_TRAY_H_
 #define ASH_SYSTEM_WEB_NOTIFICATION_WEB_NOTIFICATION_TRAY_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 116 matching lines @@
 
   void UpdateTrayContent();
 
   // The actual process to show the message center. Set |show_settings| to true
   // if the message center should be initialized with the settings visible.
   // Returns true if the center is successfully created.
   bool ShowMessageCenterInternal(bool show_settings);
 
   // Queries login status and the status area widget to determine visibility of
   // the message center.
-  bool ShouldShowMessageCenter();
+  bool ShouldShowMessageCenter() const;
 
   // Returns true if it should show the quiet mode menu.
   bool ShouldShowQuietModeMenu(const ui::Event& event);
 
   // Shows the quiet mode menu.
   void ShowQuietModeMenu(const ui::Event& event);
 
   // Creates the menu model for quiet mode and returns it.
   ui::MenuModel* CreateQuietModeMenu();
 
   WebNotificationBubbleWrapper* message_center_bubble() const {
     return message_center_bubble_.get();
   }
 
-  // Returns true if any user is logged in and the system is not at the screen
-  // for adding a secondary user.
-  bool IsLoggedIn() const;
-
   // Testing accessors.
   bool IsPopupVisible() const;
   message_center::MessageCenterBubble* GetMessageCenterBubbleForTest();
 
   WmWindow* status_area_window_;
   SystemTray* system_tray_;
   std::unique_ptr<message_center::MessageCenterTray> message_center_tray_;
   std::unique_ptr<WebNotificationBubbleWrapper> message_center_bubble_;
   std::unique_ptr<message_center::MessagePopupCollection> popup_collection_;
   std::unique_ptr<WebNotificationImage> bell_icon_;
@@ skipping 15 matching lines @@
   bool should_block_shelf_auto_hide_;
 
   std::unique_ptr<AshPopupAlignmentDelegate> popup_alignment_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(WebNotificationTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_WEB_NOTIFICATION_WEB_NOTIFICATION_TRAY_H_