UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Steps to reproduce the problem:
1. 
2. 
3. 

What is the expected behavior?
To have a policy to have users always choose download location.

What went wrong?
There is an option in chrome to have user always choose the location where to save the download.  I would like to have this in a policy.  We have an educational environment. When students download large files, they do not have enough room in the homedirectory.  I want to give the ability to save to a external drive.

Did this work before? No 

Chrome version: 61.0.3163.100  Channel: stable
OS Version: 10.0
Flash Version: