Remove auto raw pointer deduction from non-linux specific code.

ash/system/chromeos/screen_layout_observer_unittest.cc

Index: ash/system/chromeos/screen_layout_observer_unittest.cc
diff --git a/ash/system/chromeos/screen_layout_observer_unittest.cc b/ash/system/chromeos/screen_layout_observer_unittest.cc
index d468ee2665c8399c667101a4165ff7e1dedff63d..caa0e769e58588c14f29b7096855cf1027dec186 100644
--- a/ash/system/chromeos/screen_layout_observer_unittest.cc
+++ b/ash/system/chromeos/screen_layout_observer_unittest.cc
@@ -94,7 +94,7 @@ const message_center::Notification*
 ScreenLayoutObserverTest::GetDisplayNotification() const {
   const message_center::NotificationList::Notifications notifications =
       message_center::MessageCenter::Get()->GetVisibleNotifications();
-  for (const auto& notification : notifications) {
+  for (auto* notification : notifications) {
     if (notification->id() == ScreenLayoutObserver::kNotificationId)
       return notification;
   }