Thanks for writing in! Regretfully there is no feature in X/Cornerstone that you can close a particualr bar section. Perhaps a 3rd party plugin could help you with that. You may install ConvertPlus and use the Info bar feature from this plugin. You can install it by going to X > Overview > Extensions. To know more about this plugin and how we have integrated this in the theme, please check this out:
Hope this helps.