[BUG] Clicking the "Viewed (by me)" checkbox when doing reviews causes an annoying time consuming "jump"

Summary

pressing this checkbox causes the "file" to "collapse" which instead of bringing the next file to the top of the page or at least keeping the bottom of the file in a consistent place on the screen. So I am forced to scroll back up to the place I should just be without scrolling.

Steps to reproduce

Example Project

This happens on every project I've tried, please jump into any pending MR (that isn't too tiny) or make a new dummy MR with ~5 files with lots of (random) changes.

What is the current bug behavior?

The page jumps down the lines of a file I haven't looked at yet.

What is the expected correct behavior?

I can continue reviewing unimpeded by the need to scroll back up to the start of the following file B after collapsing file A.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes

No idea.