chromeos: Simplify ShutdownPolicyHandler

ash/common/system/date/date_default_view.cc

Index: ash/common/system/date/date_default_view.cc
diff --git a/ash/common/system/date/date_default_view.cc b/ash/common/system/date/date_default_view.cc
index 8eedc082f0d7a95f217810b2e8b70985bfd0b1a1..9dc87bc3433097a3318a9a413e1e41ab27d4f8fe 100644
--- a/ash/common/system/date/date_default_view.cc
+++ b/ash/common/system/date/date_default_view.cc
@@ -103,8 +103,8 @@ DateDefaultView::DateDefaultView(SystemTrayItem* owner, LoginStatus login)
   }
   SystemTrayDelegate* system_tray_delegate = shell->system_tray_delegate();
   system_tray_delegate->AddShutdownPolicyObserver(this);
-  system_tray_delegate->ShouldRebootOnShutdown(base::Bind(
-      &DateDefaultView::OnShutdownPolicyChanged, weak_factory_.GetWeakPtr()));
+  // Will invoke OnShutdownPolicyChanged with the initial value.
+  system_tray_delegate->CheckIfRebootOnShutdown();
 #endif  // !defined(OS_WIN)
 }