Setting TouchEvents API to "Automatic" or "Enabled" in chrome://flags/#touch-events did not mitigate the issue.

+ Enteprise Leads/PM/TPM) ( georgesak@, robertshield@, goanuj@, bheenan@)

Removing the Enterprise label as this label means that the issue is related to enterprise management / policies.
Please re-add it if you think it is related to that.

As per comment# 0 from the reporter, issue requires two or more touchscreen devices to test and confirm the issue. TE doesn't have enough touchscreen devices to test and confirm it, hence adding TE-Hardware-Dependency label to it.

Thanks!

This doesn't look like an enterprise specific issue, let me know if I missed something.

I think that last label was removed by mistake, so adding it back. But since this isn't an enterprise-related bug, modifying the cc list

Can also be reproduced if only the second screen is a touch screen (ie. a touchscreen on a notebook), and the first screen is a regular, non-touch screen.

Navid, we should have some external touchscreens in WAT, could you have someone take a look? A bisect would be most helpful.

This doesn't look like a Blink-specific problem: tapping on tab bar fails too, see the video.

Lan, could you try this locally and see whether we get touch events from Windows or not in this case? I wonder if it has anything to do with the switch to WM_Pointer or not.
As mustaq@ said it doesn't have anything to do with Blink though. Not sure who the right owner is.

The issue happens on both Chrome artifacts (ie. the ... settings icon) as well as the HTML document area.

I will try it on the touch screens in our lab.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5f78358dbdfa7b1a89e3359e8de45b25a7db3ec6

commit 5f78358dbdfa7b1a89e3359e8de45b25a7db3ec6
Author: lanwei <lanwei@chromium.org>
Date: Thu Nov 29 01:16:33 2018

Fix touch events not working on multi-screen

If we have more than one touch monitor and we are expanding chrome
window to all the touch screens, we can only touch on one screen not
the others. We found out the when we searched for targets of the touch
events, we could not find the right target, which should be
"RenderWidgetHostViewAura", because we are checking if the screen
locations of the touch events are in the display's bound, which only
matches to one monitor. We should change to screen's bound, which
can represent the bound of all the screens that are connected.

Bug:  901399 
Change-Id: I9c85d6e81d0d1bbaf023f566b1512a5c7b839625
Reviewed-on: https://chromium-review.googlesource.com/c/1354125
Commit-Queue: Lan Wei <lanwei@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611975}
[modify] https://crrev.com/5f78358dbdfa7b1a89e3359e8de45b25a7db3ec6/ui/aura/window_targeter.cc

Tried testing the issue as per comment# 12 with touch screen and non-touch screen where in our case first screen is touch screen and second screen is Non-touch screen, but unable to reproduce the issue.

@ttpennersap: Could you please try to test this issue on latest chrome# 72.0.3625.0 and help us in verifying the fix.

Thanks!

As per Alexander Nohe's direction, we tried the dev version 72 from https://www.chromium.org/getting-involved/dev-channel

However, the problem still exists: I move the Chrome window in screen 2, then drag it across screen 1 and 2, now touch only works on screen 2 but not 1. Please see attached picture.

Thanks,
Sheng Li

Development Manager, SAP Analytics Cloud

Deleted: touch-Chrome-2nd-screen.jpeg 74.0 KB

	touch-Chrome-2nd-screen.jpeg 74.0 KB View Download

Dev version doesn't include fix listed at #20. Please check test latest canary version 72.0.3625.0 (https://www.google.com/chrome/canary/).

This bug requires manual review: We are only 4 days from stable.
Please contact the milestone owner if you have questions.
Owners: benmason@(Android), kariahda@(iOS), kbleicher@(ChromeOS), govind@(Desktop)

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

This is regressed in M70 and M71 is going to stable next week. Pls provide merge justification and comment on safety.  Pls note unless this is extremely critical and safe, we can't take this merge in for M71 this late in release cycle. 

since this is reported by SAP, and they are complaining that this is affecting all of their digital boardroom customers and is in the millions of dollars affected range for revenue.
I think it is a very safe change, it is a small change, we just change the behavior in some platforms, and it is reverted to an old code.

Thank you lanwei@. 
Pls verify this on latest canary version 72.0.3625.0 (https://www.google.com/chrome/canary/) and update bug with canary result.

Just heard from our partner that the fix was observed to have worked in canary.

Approving merge to M71 branch 3578 based on comment #27, #29 and per internal mail thread/chat with lanwei@. Pls merge ASAP. Thank you.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ebe88136ed6e765f68ef67f9de1ab3d5ac5f8e08

commit ebe88136ed6e765f68ef67f9de1ab3d5ac5f8e08
Author: Lan Wei <lanwei@chromium.org>
Date: Thu Nov 29 23:06:46 2018

Fix touch events not working on multi-screen

If we have more than one touch monitor and we are expanding chrome
window to all the touch screens, we can only touch on one screen not
the others. We found out the when we searched for targets of the touch
events, we could not find the right target, which should be
"RenderWidgetHostViewAura", because we are checking if the screen
locations of the touch events are in the display's bound, which only
matches to one monitor. We should change to screen's bound, which
can represent the bound of all the screens that are connected.

TBR=lanwei@chromium.org

(cherry picked from commit 5f78358dbdfa7b1a89e3359e8de45b25a7db3ec6)

Bug:  901399 
Change-Id: I9c85d6e81d0d1bbaf023f566b1512a5c7b839625
Reviewed-on: https://chromium-review.googlesource.com/c/1354125
Commit-Queue: Lan Wei <lanwei@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#611975}
Reviewed-on: https://chromium-review.googlesource.com/c/1356018
Reviewed-by: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/branch-heads/3578@{#855}
Cr-Branched-From: 4226ddf99103e493d7afb23a4c7902ee496108b6-refs/heads/master@{#599034}
[modify] https://crrev.com/ebe88136ed6e765f68ef67f9de1ab3d5ac5f8e08/ui/aura/window_targeter.cc

The following revision refers to this bug: 
https://chromium.googlesource.com/chromium/src.git/+/ebe88136ed6e765f68ef67f9de1ab3d5ac5f8e08

Commit: ebe88136ed6e765f68ef67f9de1ab3d5ac5f8e08
Author: lanwei@chromium.org
Commiter: lanwei@chromium.org
Date: 2018-11-29 23:06:46 +0000 UTC

Fix touch events not working on multi-screen

If we have more than one touch monitor and we are expanding chrome
window to all the touch screens, we can only touch on one screen not
the others. We found out the when we searched for targets of the touch
events, we could not find the right target, which should be
"RenderWidgetHostViewAura", because we are checking if the screen
locations of the touch events are in the display's bound, which only
matches to one monitor. We should change to screen's bound, which
can represent the bound of all the screens that are connected.

TBR=lanwei@chromium.org

(cherry picked from commit 5f78358dbdfa7b1a89e3359e8de45b25a7db3ec6)

Bug:  901399 
Change-Id: I9c85d6e81d0d1bbaf023f566b1512a5c7b839625
Reviewed-on: https://chromium-review.googlesource.com/c/1354125
Commit-Queue: Lan Wei <lanwei@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#611975}
Reviewed-on: https://chromium-review.googlesource.com/c/1356018
Reviewed-by: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/branch-heads/3578@{#855}
Cr-Branched-From: 4226ddf99103e493d7afb23a4c7902ee496108b6-refs/heads/master@{#599034}

SAP verified the fix in Windows canary.