Implement Non-Closable Notification

ui/message_center/message_center_impl.cc

Index: ui/message_center/message_center_impl.cc
diff --git a/ui/message_center/message_center_impl.cc b/ui/message_center/message_center_impl.cc
index ada49c8abafbe5c558df1392f7540f087e8bcf6b..72eaf3b3331d4364ee7353d177745f5c133d60dd 100644
--- a/ui/message_center/message_center_impl.cc
+++ b/ui/message_center/message_center_impl.cc
@@ -646,20 +646,34 @@ void MessageCenterImpl::RemoveNotificationsForNotifierId(
 void MessageCenterImpl::RemoveAllNotifications(bool by_user) {
   // Using not |blockers_| but an empty list since it wants to remove literally
   // all notifications.
-  RemoveNotifications(by_user, NotificationBlockers());
+  RemoveNotifications(by_user,
+                      false /* closable only */,
+                      NotificationBlockers());
 }
 
 void MessageCenterImpl::RemoveAllVisibleNotifications(bool by_user) {
-  RemoveNotifications(by_user, blockers_);
+  RemoveNotifications(by_user,
+                      false /* closable only */,
+                      blockers_);
+}
+
+void MessageCenterImpl::RemoveAllClosableNotifications(bool by_user) {
+  RemoveNotifications(by_user,
+                      true /* closable only */,
+                      blockers_);
 }
 
 void MessageCenterImpl::RemoveNotifications(
     bool by_user,
+    bool only_closable,
     const NotificationBlockers& blockers) {
   const NotificationList::Notifications notifications =
       notification_list_->GetVisibleNotifications(blockers);
   std::set<std::string> ids;
   for (const auto& notification : notifications) {
+    if (only_closable && !notification->closable())
+      continue;
+
     ids.insert(notification->id());
     scoped_refptr<NotificationDelegate> delegate = notification->delegate();
     if (delegate.get())