@Wimpy Thanks for posting. Great that this is built into 15.04. Setting it up manually can be daunting when you keep losing Window Decoration! 
I had enabled in my Unity 14.04 + your Mate PPA after you’d added the option in Mate Tweak, but the feature I really wanted - rotate viewport on scroll on desktop wasn’t there, so I’d given up with Compiz.
Your video post encouraged me to try one more time, and success! Turns out it was not any of your canned settings affecting it, but a default setting change in Compiz - since 10.04! :roll:
For the benefit of others … to enable viewport switching when you scroll up/down with cursor over any empty part of the desktop, go to Compiz Settings Manager > Desktop > Viewport Switcher > Desktop-based Viewport Swicthing and either set Move Left to Button4 and Move Right to Button5 or set Move Next to Button5 and Move previous to Button4 (note subtle change of button order!).
If you use Move Left/Right scroll down will rotate right indefinitely, but scroll up will stop at Viewport 1. Using Move Next/Previous both up and down will rotate indefinitely.