chromeos: Simplify ShutdownPolicyHandler

ash/common/system/tiles/tiles_default_view.cc

Index: ash/common/system/tiles/tiles_default_view.cc
diff --git a/ash/common/system/tiles/tiles_default_view.cc b/ash/common/system/tiles/tiles_default_view.cc
index 92a0e60eed15259ae43ea3954225d1c0de7a68ce..233b109f7284c4da77df3ae3d4fb47100667f93f 100644
--- a/ash/common/system/tiles/tiles_default_view.cc
+++ b/ash/common/system/tiles/tiles_default_view.cc
@@ -111,8 +111,8 @@ void TilesDefaultView::Init() {
   AddChildView(power_button_);
   SystemTrayDelegate* system_tray_delegate = shell->system_tray_delegate();
   system_tray_delegate->AddShutdownPolicyObserver(this);
-  system_tray_delegate->ShouldRebootOnShutdown(base::Bind(
-      &TilesDefaultView::OnShutdownPolicyChanged, weak_factory_.GetWeakPtr()));
+  // Will invoke OnShutdownPolicyChanged with the initial value.
+  system_tray_delegate->CheckIfRebootOnShutdown();
 #endif  // !defined(OS_WIN)
 }