You should have some kind of content that includes (a form with) a html select element. For testing you could create a custom html module containing just a select element with two options. [Edit: See next post for demo code]
Set Mouse over Edit icons to Modules and menus (in System > Global configuration)
Then, using Firefox (Windows or Mac) log into the front end as an admin and navigate to your module. Click the select element and try to select the second option.
Applied the patch and tested good in Firefox 40. Other browsers tested good too.