Revert of Update first download notification correctly if there are multiple notifications

chrome/browser/download/notification/download_notification_manager.cc

Index: chrome/browser/download/notification/download_notification_manager.cc
diff --git a/chrome/browser/download/notification/download_notification_manager.cc b/chrome/browser/download/notification/download_notification_manager.cc
index 6eb6b493bd565ab8ea65489517e83afc435913f4..a91349b7eb1ba9353247a27cd08291b6ce530216 100644
--- a/chrome/browser/download/notification/download_notification_manager.cc
+++ b/chrome/browser/download/notification/download_notification_manager.cc
@@ -78,7 +78,6 @@
     DownloadNotificationManager* parent_manager)
     : profile_(profile),
       parent_manager_(parent_manager),
-      message_center_(g_browser_process->message_center()),
       items_deleter_(&items_) {
 }
 
@@ -154,9 +153,3 @@
   DownloadItemNotification* item = new DownloadItemNotification(download, this);
   items_.insert(std::make_pair(download, item));
 }
-
-void DownloadNotificationManagerForProfile::OverrideMessageCenterForTest(
-    message_center::MessageCenter* message_center) {
-  DCHECK(message_center);
-  message_center_ = message_center;
-}