What happened to the "Close Chat" option?

I just updated my OSX to 10.8.2 and noticed that I cannot close a conversation in Messages without deleting it. Before the update, I was able to menu-click on a conversation & select "Close Chat" to close the conversation from the list without clearing the chat history.

After the 10.8.2 update, now the option says "Delete Chat..." and I can't figure out how to close a conversation without clearing the history. Any thoughts?