Is there someone who can own this?

I will have it for now, but probably won't be able to start working on it till next quarter.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ea218ea3a49dc7edf2aca2f948c62b97860557b8

commit ea218ea3a49dc7edf2aca2f948c62b97860557b8
Author: Sahel Sharify <sahel@chromium.org>
Date: Fri May 11 18:04:29 2018

Smooth scrolling returns DROP_EVENT when the scroller is at its extent.

InputHandlerProxy::HandleGestureScrollUpdate returns DROP_EVENT for the
common scrolling path when the scroller is at its extent and the event
hasn't caused any scroll. This cl makes sure that the function also
returns DROP_EVENT for the smooth (animated) scroll path when the
scroller is at its extent.

This change is necessary for excluding the GSU events that arrive when
the scroller is at its extent from scrolling performance metrics.

Bug:  773740 
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I6bfa93da23728888c16e673e21b881ab5f6baac4
Reviewed-on: https://chromium-review.googlesource.com/1054529
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Sahel Sharifymoghaddam <sahel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557931}
[modify] https://crrev.com/ea218ea3a49dc7edf2aca2f948c62b97860557b8/cc/trees/layer_tree_host_impl.cc
[modify] https://crrev.com/ea218ea3a49dc7edf2aca2f948c62b97860557b8/cc/trees/layer_tree_host_impl_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/43164af2497a33721f9d6559ab9f1646cec7a595

commit 43164af2497a33721f9d6559ab9f1646cec7a595
Author: Sahel Sharify <sahel@chromium.org>
Date: Wed Jun 06 22:42:21 2018

Latency info terminated while scrolling against the scroll extent.

We already skip recording scroll metrics when the GSU events are ignored
since ignored events don't cause GPU swap.
This cl terminates the latency info from ignored GSU events and adds a
unittest to verify the termination. It also has a browsertest to verify
no scroll latency gets recorded when GSU events are ignored.

ScrollLatencyBrowserTest.ScrollLatencyNotRecordedIfGSUIgnored

Bug:  773740 
Test: RenderWidgetHostLatencyTrackerTest.LatencyTerminatedOnAckIfGSUIgnored,
Change-Id: Idaa4c3d739a79a8e44e4c3db82a74877428d404c
Reviewed-on: https://chromium-review.googlesource.com/1080035
Commit-Queue: Sahel Sharifymoghaddam <sahel@chromium.org>
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Reviewed-by: Navid Zolghadr <nzolghadr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565069}
[modify] https://crrev.com/43164af2497a33721f9d6559ab9f1646cec7a595/content/browser/renderer_host/input/render_widget_host_latency_tracker.cc
[modify] https://crrev.com/43164af2497a33721f9d6559ab9f1646cec7a595/content/browser/renderer_host/input/render_widget_host_latency_tracker_unittest.cc
[modify] https://crrev.com/43164af2497a33721f9d6559ab9f1646cec7a595/content/browser/renderer_host/input/scroll_latency_browsertest.cc