Regression: moving when typing in annoying way

[gwpl]

It looks like placement of AD banner changed affecting whole layout.

Now when I type on my 1200px wide (and 1600hight - pivotal) screen,
middle box when I type is "shaking" when I type (getting more narrow/wider),
it's visually super disturbing.

[gwpl]

I just tested with older version I downloaded to harddrive in past, and there is same issue, so it's possible that something has changed in how Chromium does layout.