The chat list with changed number of unread messages.
Total number of chats marked as unread.
Total number of unmuted chats marked as unread.
Approximate total number of chats in the chat list.
Total number of unread chats.
Total number of unread unmuted chats.
Number of unread chats, i.e. with unread messages or marked as unread, has changed. This update is sent only if the message database is used. Subtype of Update.