The 1st patch to disambiguate message center notifications

ash/system/chromeos/screen_security/screen_tray_item_unittest.cc

Index: ash/system/chromeos/screen_security/screen_tray_item_unittest.cc
diff --git a/ash/system/chromeos/screen_security/screen_tray_item_unittest.cc b/ash/system/chromeos/screen_security/screen_tray_item_unittest.cc
index 027d81c304e785f02df5e20bc8a7be3771df037d..2396c81417939f7fdb5fe8fd4d8592f54d260418 100644
--- a/ash/system/chromeos/screen_security/screen_tray_item_unittest.cc
+++ b/ash/system/chromeos/screen_security/screen_tray_item_unittest.cc
@@ -181,7 +181,8 @@ void TestNotificationView(ScreenTrayItemTest* test) {
   test->StartSession();
   message_center::MessageCenter* message_center =
       message_center::MessageCenter::Get();
-  EXPECT_TRUE(message_center->HasNotification(tray_item->GetNotificationId()));
+  EXPECT_TRUE(message_center->FindVisibleNotificationById(
+      tray_item->GetNotificationId()) != NULL);
   test->StopSession();
 }