[Launcher per display] Removed Shell::status_area_widget(), system_tray()

ash/system/tray_update.cc

Index: ash/system/tray_update.cc
diff --git a/ash/system/tray_update.cc b/ash/system/tray_update.cc
index ef352ebc11e43376a6468e01d672c73d609e94b2..67aa2b30d78b45a2b57b3a54784f13c07aef571b 100644
--- a/ash/system/tray_update.cc
+++ b/ash/system/tray_update.cc
@@ -108,7 +108,7 @@ class UpdateNagger : public ui::LayerAnimationObserver {
 
   virtual ~UpdateNagger() {
     internal::StatusAreaWidget* status_area =
-        ash::Shell::GetInstance()->status_area_widget();
+        Shell::GetPrimaryRootWindowController()->status_area_widget();
     if (status_area) {
       status_area->system_tray()->GetWidget()->GetNativeView()->layer()->
           GetAnimator()->RemoveObserver(this);