The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ddfc352c8851b8eaee293446048316c84cbabc7d

commit ddfc352c8851b8eaee293446048316c84cbabc7d
Author: ymalik <ymalik@chromium.org>
Date: Mon Sep 05 18:40:37 2016

Take MT jank into account when animating the scroll offset on CC

This CL calculates the jank by subtracting base::TimeTicks::Now from
the event platform time when GestureScrollUpdate is called.

BUG= 616995 
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel

Review-Url: https://codereview.chromium.org/2040543002
Cr-Commit-Position: refs/heads/master@{#416561}

[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/animation_host.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/animation_host.h
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/animation_host_unittest.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/scroll_offset_animation_curve.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/scroll_offset_animation_curve.h
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/scroll_offset_animation_curve_unittest.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/scroll_offset_animations_impl.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/animation/scroll_offset_animations_impl.h
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/input/input_handler.h
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/layers/viewport.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/layers/viewport.h
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/trees/layer_tree_host_impl.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/trees/layer_tree_host_impl.h
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/trees/layer_tree_host_impl_unittest.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/cc/trees/layer_tree_host_unittest_animation.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/ui/events/blink/input_handler_proxy.cc
[modify] https://crrev.com/ddfc352c8851b8eaee293446048316c84cbabc7d/ui/events/blink/input_handler_proxy_unittest.cc

Isn't there another side of this for scrolls animated on the main thread?

Oops you're right. Re-opening.

My patch in comment 4 does this for the impl thread. To do this on the main thread, we need to plumb event information to the ScrollAnimator and take that into account when creating / updating the animation curve.

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. If you change it back, also remove the "Hotlist-Recharge-Cold" label.

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

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

I believe this will be addressed with scroll unification work folks are working on. bokan@ can you confirm this? Is there a bug we can mark this as duplicate of that?

That's my expectation, yes, since the animation would always be started from the compositor thread.