arc: OnClosedFromAndroid removes notifications as not by_user

ui/arc/notification/arc_notification_manager.cc

Index: ui/arc/notification/arc_notification_manager.cc
diff --git a/ui/arc/notification/arc_notification_manager.cc b/ui/arc/notification/arc_notification_manager.cc
index 40f8ea426098a7f0c3a184cece63feb0a6407cbc..00a89d639b79d4a87f362b3da3411a6da962cd2f 100644
--- a/ui/arc/notification/arc_notification_manager.cc
+++ b/ui/arc/notification/arc_notification_manager.cc
@@ -101,7 +101,7 @@ void ArcNotificationManager::OnNotificationRemoved(const mojo::String& key) {
 
   std::unique_ptr<ArcNotificationItem> item = std::move(it->second);
   items_.erase(it);
-  item->OnClosedFromAndroid(true /* by_user */);
+  item->OnClosedFromAndroid(false /* by_user */);

[yoshiki, 2016/10/06 06:37:13]

Could you remove the "by_user" argument from
ArcNotificationItem::OnClosedFromAndroid() and to pass "false" directly from
inside of ArcNotificationItem::OnClosedFromAndroid()?

I think that's better than passing false from here.

[xiyuan, 2016/10/06 16:15:41]

Sounds good. Done.

 }
 
 void ArcNotificationManager::SendNotificationRemovedFromChrome(