The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0774dcc15d6c7f59bcca77b5c2d1288b49911707

commit 0774dcc15d6c7f59bcca77b5c2d1288b49911707
Author: eugenebut <eugenebut@chromium.org>
Date: Thu Dec 22 00:07:06 2016

[ios] Fixed web-compat bug related to resetting top content inset.

OverscrollActionsController resets top content inset every time when
scolling is finished. Before this change it assumed that bottom inset
should be always reset to 0. This is not correct for cases when soft
keyboard is displayed and bottom offset is non-zero to accomodate the
keyboard.

This CL adds resetScrollViewTopContentInset method and calls it when
scrolling is finished. Remaining fixed will be landed in separate CLs
to make changes less risky.

BUG= 669908 ,675763

Review-Url: https://codereview.chromium.org/2589973004
Cr-Commit-Position: refs/heads/master@{#440273}

[modify] https://crrev.com/0774dcc15d6c7f59bcca77b5c2d1288b49911707/ios/chrome/browser/ui/overscroll_actions/overscroll_actions_controller.mm

I don't have evidence that setting 0 bottom inset causes web-compat bugs, but it probably does.

Eugene, was your fix sufficient for this bug? Do you know of an example of a website that's broken by this?

There are a few other places where OverscrollActionsController can reset content offset. And I'm not aware about any other affected sites.

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot