Related to issue 879791. https://chromium-review.googlesource.com/1249152 is landed and we should revisit this.

Most tests fails because of issue 895029 where WS adds a frame sink id in HitTestQuery's hit test data and is not handled properly.

 Issue 884366  has been merged into this issue.

 Issue 884369  has been merged into this issue.

 Issue 889301  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5cb30fcac9f26c0126cf5e7e1ff224ec94d98886

commit 5cb30fcac9f26c0126cf5e7e1ff224ec94d98886
Author: Xiyuan Xia <xiyuan@chromium.org>
Date: Fri Oct 19 22:01:03 2018

ws: HitTestQuery uses GetTransformToTarget

HitTestQuery uses GetTransformToTarget when Window Service
is in use because there is a ClientRoot frame sink id in
hit test data that the browser process does not know thus
could not put it in |target_ancestors| to go the optimized
transform code path. Use GetTransformToTarget to correctly
transform location with Window Service.

Also remove the ClientRoot frame sink id from the hit test data
used in a bunch of OOPIF tests that use a direct index into hit
test data.

Bug:  884360 , 895029
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel
Change-Id: I0943e7719e7fb418eaa2304765376b31065eea07
Reviewed-on: https://chromium-review.googlesource.com/c/1281167
Reviewed-by: Ria Jiang <riajiang@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601312}
[modify] https://crrev.com/5cb30fcac9f26c0126cf5e7e1ff224ec94d98886/components/viz/host/hit_test/hit_test_query.cc
[modify] https://crrev.com/5cb30fcac9f26c0126cf5e7e1ff224ec94d98886/content/browser/renderer_host/render_widget_host_view_base.cc
[modify] https://crrev.com/5cb30fcac9f26c0126cf5e7e1ff224ec94d98886/content/browser/site_per_process_hit_test_browsertest.cc
[modify] https://crrev.com/5cb30fcac9f26c0126cf5e7e1ff224ec94d98886/testing/buildbot/filters/chromeos.single_process_mash.content_browsertests.filter

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1da15ee05d5ddc0d880acdfaac5ac3117b6224fe

commit 1da15ee05d5ddc0d880acdfaac5ac3117b6224fe
Author: Xiyuan Xia <xiyuan@chromium.org>
Date: Fri Oct 19 23:43:24 2018

Fix CrossProcessMouseEnterAndLeaveTest in mash

Fix CrossProcessMouseEnterAndLeaveTest by waiting for initial
mouse event to be dispatched because the event is asynchronously
dispatched in mash.

Bug:  884360 
Change-Id: I4f40accfb9077e6bb8ccab5128b42c66493e84ed
Reviewed-on: https://chromium-review.googlesource.com/c/1292398
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601357}
[modify] https://crrev.com/1da15ee05d5ddc0d880acdfaac5ac3117b6224fe/content/browser/site_per_process_hit_test_browsertest.cc
[modify] https://crrev.com/1da15ee05d5ddc0d880acdfaac5ac3117b6224fe/testing/buildbot/filters/chromeos.single_process_mash.content_browsertests.filter

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/45ebea3c754ecff1254c2211702555d8ab96f6ff

commit 45ebea3c754ecff1254c2211702555d8ab96f6ff
Author: Xiyuan Xia <xiyuan@chromium.org>
Date: Mon Nov 05 22:29:48 2018

Fix SubframeGestureEventRouting in mash

- Add a ScopedAllow helper class that SystemEventRewriter allows
  event to pass through when there are instances of it;
- Use ScopedAllow helper to allow fake gesture events to pass
  through under mash;

Bug:  884360 
Change-Id: I940398b0920505743ad7adbe08e12e1394fb55c0
Reviewed-on: https://chromium-review.googlesource.com/c/1292400
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605496}
[modify] https://crrev.com/45ebea3c754ecff1254c2211702555d8ab96f6ff/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash_browsertest.cc
[modify] https://crrev.com/45ebea3c754ecff1254c2211702555d8ab96f6ff/content/browser/site_per_process_hit_test_browsertest.cc
[modify] https://crrev.com/45ebea3c754ecff1254c2211702555d8ab96f6ff/testing/buildbot/filters/chromeos.single_process_mash.content_browsertests.filter

This bug is marked fixed but there's still one test filter that's linked to it, i.e. SitePerProcessHitTestBrowserTest.CrossProcessTooltipTest*. What monorail issue should that one be pointing at?

Good call. Forgot that one. Reopen.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c78328feba0d2409b5fdf00e188f6ca039966606

commit c78328feba0d2409b5fdf00e188f6ca039966606
Author: Xiyuan Xia <xiyuan@chromium.org>
Date: Tue Nov 06 19:28:37 2018

Enable CrossProcessTooltipTest for mash

Fixed with https://chromium-review.googlesource.com/c/1281167
and no longer fails for mash.

Bug:  884360 
Change-Id: If5fe9b326eb2f8b73b3af900631ef3b0fb8263f8
Reviewed-on: https://chromium-review.googlesource.com/c/1320196
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605785}
[modify] https://crrev.com/c78328feba0d2409b5fdf00e188f6ca039966606/testing/buildbot/filters/chromeos.single_process_mash.content_browsertests.filter