Here is an option to auto hide a toolbar in the Mozilla browser. You will need to add up the below code in chrome.css. See the below code and open you chrome.css. Then copy paste the code in that. Exit it and restart your browser. Now if you move the mouse pointer on the top menu then the bookmark toolbar will popup. If you remove the pointer then after some time it will disappear.
HTML Code:
/* Pop-up bookmarks toolbar */ #PersonalToolbar {display: none;} #navigator-toolbox:hover > #PersonalToolbar {display: -moz-box;}
Bookmarks