Damn, this site is incredibly hard to find if you don't get the search terms exactly right. And I ended up being displeased with the selection.

So I made my own animation that's tileable, meaning the progress bar can be as long and scalable as you want. Just set it as the background-image of the block element. Use it if you want! You can see it in action at sucks/rocks.

tileable animated progress bar

And in the reverse direction:

tileable animated progress bar reverse

And here it is tiled: