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

ash/system/tray/system_tray_delegate.h

Index: ash/system/tray/system_tray_delegate.h
diff --git a/ash/system/tray/system_tray_delegate.h b/ash/system/tray/system_tray_delegate.h
index 4eace68e72e0682c7a9909205ec53f33face31d3..8cb3f2c9b8cae2188f6cfc877fc7cb18f501c07c 100644
--- a/ash/system/tray/system_tray_delegate.h
+++ b/ash/system/tray/system_tray_delegate.h
@@ -86,12 +86,6 @@ class ASH_EXPORT SystemTrayDelegate {
   // crbug.com/443119
   virtual bool IsUserChild() const;
 
-  // Returns true if settings menu item should appear.
-  virtual bool ShouldShowSettings() const;
-
-  // Returns true if notification tray should appear.
-  virtual bool ShouldShowNotificationTray() const;
-
   // Shows information about enterprise enrolled devices.
   virtual void ShowEnterpriseInfo();