I am on Ubuntu 12.04 and installed gnome-shell, but I found the top bar is larger than it normally is, how can I change its size?
The most simplistic way is to simply click on it with:
Hold both "Windows key + Alt" then "Right-click" the bar.
Then click "Properties".
In the "General Tab", simply resize the bar.
Find the file
open it for editing by running the command
then in that file right in the begining you'll see
and save the file, now you have changed the font size for the shell which will resize the top bar too, but now you need to restart the theme to load this file
so press alt + F2 and enter
It shall work I'm not using ubuntu but it works for me on fedora