Some more fixes to cros system tray icons (esp. screen tray items)

ash/common/system/user/tray_user_separator.h

Index: ash/common/system/user/tray_user_separator.h
diff --git a/ash/common/system/user/tray_user_separator.h b/ash/common/system/user/tray_user_separator.h
index 89e2757300a82e50faa3141944eefbb37e47baff..6255060d3cb20dbc178368c45790b1d48da3bbdd 100644
--- a/ash/common/system/user/tray_user_separator.h
+++ b/ash/common/system/user/tray_user_separator.h
@@ -25,11 +25,7 @@ class ASH_EXPORT TrayUserSeparator : public SystemTrayItem {
  private:
   // Overridden from SystemTrayItem.
   views::View* CreateDefaultView(LoginStatus status) override;
-  void DestroyTrayView() override {}
   void DestroyDefaultView() override;
-  void DestroyDetailedView() override {}
-  void UpdateAfterLoginStatusChange(LoginStatus status) override {}
-  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override {}
 
   // True if the separator gets shown.
   bool separator_shown_;