Automatically close the default push notification when a real one appears.

chrome/browser/push_messaging/push_messaging_notification_manager.cc

Index: chrome/browser/push_messaging/push_messaging_notification_manager.cc
diff --git a/chrome/browser/push_messaging/push_messaging_notification_manager.cc b/chrome/browser/push_messaging/push_messaging_notification_manager.cc
index e02d170a7bac38098bc833fd2607673ca3857dcc..d082993b7f7da97c8dd5e52ad4b485ff986d2ace 100644
--- a/chrome/browser/push_messaging/push_messaging_notification_manager.cc
+++ b/chrome/browser/push_messaging/push_messaging_notification_manager.cc
@@ -143,11 +143,31 @@ void PushMessagingNotificationManager::DidGetNotificationsFromDatabase(
       notification_needed = false;
       break;
     }
-#if defined(OS_ANDROID)

[johnme, 2015/06/02 13:43:52]

Please don't remove this. The double closing brackets avoid breaking various
editors' syntax highlighters (including IIRC sublime text). Perhaps there should
be a comment explaining that.

[Peter Beverloo, 2015/06/02 13:58:08]

I'm having a very hard time accepting that reasoning John. This code is not
cool.

I've reverted it for the sake of this patch since we want to merge it, but I
really want to see this go.

   }
-#else
+
+  // If more than two notifications are showing for this Service Worker, close
+  // the default notification if it happens to be part of this group.
+  if (notification_count >= 2) {
+    for (const auto& notification_database_data : data) {
+      if (notification_database_data.notification_data.tag !=
+          kPushMessagingForcedNotificationTag)
+        continue;
+
+      PlatformNotificationServiceImpl* platform_notification_service =
+          PlatformNotificationServiceImpl::GetInstance();
+
+      // First close the notification for the user's point of view, and then
+      // manually tell the service that the notification has been closed in
+      // order to avoid duplicating the thread-jump logic.
+      platform_notification_service->ClosePersistentNotification(
+          profile_, notification_database_data.notification_id);
+      platform_notification_service->OnPersistentNotificationClose(
+          profile_, notification_database_data.notification_id,
+          notification_database_data.origin);
+
+      break;
+    }
   }
-#endif
 
   // Don't track push messages that didn't show a notification but were exempt
   // from needing to do so.