What steps will reproduce the problem?
(1) Detach a device like the Pixel Slate from its keyboard
(2) Open a site like The Verge or Medium in Chrome
(3) Observe how scrolling gets noticeably jankier and unreliable after a couple of minutes of touch scrolling

What is the expected output?
The scrolling performance should be unaffected by whether I'm in tablet or laptop mode. It definitely shouldn't get worse in tablet mode.

What do you see instead?
Touch input gets janky and unreliable. It seems as if keeping track of the finger(s) during touch events is considerably more difficult for Chrome OS to handle when in tablet mode.