Wich folder for userChrome?

I need to edit the userChrome in PFF 2.0: I searched within the directory and I get two file:

Firefox (portable)\App\DefaultData\profile\chrome\userChrome.css
Firefox (portable)\App\firefox\defaults\profile\chrome\userChrome.css

Wich one is the right one?

I tried copy the same file on both location, but I get no results (i added the .searchbar-textbox {width: 20px !important;} to resize the searchbox but it is still of the same size...)