I think this line was accidently commented out in this commit:

3d1ae3500c

The FPS limit is needed to get the desired wait time for the "hide window"
test, which uses the frame counter to hide the window for 3 seconds. On
my machine without this limit it runs at over 1000 FPS and it appears
like the hide window state is broken.

I also added some text that tells the user that it only hides the window
for 3 seconds so they're not surprised when the window automatically
reappears.