Can you confirm that it doesn't happen if smooth scrolling is disabled in about:flags?

Are there specific websites you see the issue on, or is it reproducible on any page?

It seems to independent of the page.  I will try disabling the flag and get back to you.

I have had this jump happen a few times with smooth scrolling off.  Does it still use xinput2 if smooth scrolling is off?  If there was a way to toggle that, or to log all xinput2 scroll deltas, that might help pin this down more.

(Just in case it wasn't obvious: I am pretty sure these sudden big scrolls didn't happen before my last Chrome update.)

Correct, the smooth scrolling flag does not affect the use of xinput2.  I'm not sure how to toggle that; cc'ing some folks who might know.

Forgive me from imagining from a point of ignorance, but if I had to make a guess I would guess my trackpad sometimes sends scroll events with a huge delta, and capping the scroll delta would work around the bug.  However I have no idea how you might pick such a cap without more info.  I will run "xinput --text-xi2 12" into a log for a while and see if anything interesting comes up.

 Bug 593453  comment 6 sounds related to this.

This is driving me crazy, any help?  I've gotten really good at hitting shift-spacebar a bunch of times to scroll back up when my page jumps to the bottom.  (I've been unable to get anything useful in the log mentioned in comment 6 because I keep forgetting about it when it happens -- would such a log be useful?)

PS: I have the standard issue Google laptop so I would imagine this is affecting others, but perhaps I'm the last Googler who takes Linux laptops...

What exactly is the Google issued laptop and OS?

Hewlett Packard Elitebook 840 G1 running Goobuntu.

FWIW, I'm on a Lenovo Google laptop and haven't seen this so it might be related to the specific touchpad/driver.

(Er, and Goobuntu is just Ubuntu 14.04 LTS as far as I know.)

I have had the exact same issue since a recent update(in this month, if I remember correctly)

I'm using elementary OS 0.3.2 Freya(built on Ubuntu 14.04), and Chrome dev channel. My laptop is ThinkPad SL410.

A bunch of fixes landed recently and were merged to Beta channel. Please try Beta channel once it refreshes (today's refresh didn't pick up those changes yet but anything newer than 51.0.2704.29 should have them) or Dev channel and see if the problem reproduces there.