Scrolling on large merges is laggy

[hipstersmoothie]

When working on a large merge scrolling in the file list is very laggy and not smooth. If i scrolling the files though everything scrolls very smoothly.

(left slow, right fast)

[lucasderraugh]

To help with debugging reproducibility, how many files did you have when it was laggy?

[hipstersmoothie]

I'm not sure how to get an exact number but > 200

[sjavora]

Not sure if this is the same thing, but the list on the left doesn't seem to work well with inertia scrolling - see attached video where I first scroll the right pane on a trackpad and then do the same thing on the left (excuse the green title bar, I couldn't attach a mov).