Update first download notification correctly if there are multiple notifications

chrome/browser/download/notification/download_notification_browsertest.cc

Index: chrome/browser/download/notification/download_notification_browsertest.cc
diff --git a/chrome/browser/download/notification/download_notification_browsertest.cc b/chrome/browser/download/notification/download_notification_browsertest.cc
index 4b72ddafcd3267bea4e296b8e9fd4a2e6d265bc3..6d08b3f26f9c220ce82c50cb8a3b482787034884 100644
--- a/chrome/browser/download/notification/download_notification_browsertest.cc
+++ b/chrome/browser/download/notification/download_notification_browsertest.cc
@@ -374,6 +374,11 @@ IN_PROC_BROWSER_TEST_F(DownloadNotificationTest, DownloadFile) {
   EXPECT_EQ(message_center::NOTIFICATION_TYPE_PROGRESS,
             GetNotification(notification_id())->type());
 
+  // Confirms that the download update is delivered to the notification.
+  NotificationUpdateObserver download_notification_periodically_update_observer;
+  download_item()->UpdateObservers();
+  download_notification_periodically_update_observer.Wait();
+
   NotificationUpdateObserver download_notification_update_observer;
 
   // Requests to complete the download.
@@ -784,6 +789,17 @@ IN_PROC_BROWSER_TEST_F(DownloadNotificationTest, MAYBE_DownloadMultipleFiles) {
   EXPECT_EQ(message_center::DEFAULT_PRIORITY,
             GetNotification(notification_id2)->priority());
 
+  // Confirms that the updates of both download are delivered to the
+  // notifications.
+  NotificationUpdateObserver notification_periodically_update_observer1;
+  download1->UpdateObservers();
+  EXPECT_EQ(notification_id1,
+            notification_periodically_update_observer1.Wait());
+  NotificationUpdateObserver notification_periodically_update_observer2;
+  download2->UpdateObservers();
+  EXPECT_EQ(notification_id2,
+            notification_periodically_update_observer2.Wait());
+
   // Requests to complete the downloads.
   ui_test_utils::NavigateToURL(
       browser(), GURL(net::URLRequestSlowDownloadJob::kFinishDownloadUrl));