http://feedback/#/Report/73009657086

I have also experienced this on samus.
Feedback report for missing login screen UI: 
http://feedback/#/Report/73123158740

I was able to type by password, press enter, and login without the fields being visible.

Other times, I notice that the login screen take a while to render after I lock my device.  I use the lock screen short cut and see a black screen for a few seconds until the ui renders.

alemate@, is this related to the issue you mentioned yesterday?

If not I suspect this is related to the lock screen animation changes by warx@.

I am not sure how this could happen. On m61, tablet power button and suspend (lid closed in this case) will do immediate animation for hiding non lock screen containers and shelf. Start from m62, post lock animation for the above two cases are also immediate.

It looks like in this case, lock screen containers (showing up in post lock animation) are not brought up?

+derat, abodenha. +Release-block as it seems pretty bad and more than one person is seeing it. abodenha, feel free to remove if you disagree.

I just saw this again. I left my Pixel with the lid open and went away for a while. When I came back the screen was dark. I tapped shift to wake the machine. It came on with status area visible, wifi icon animating (attempting to reacquire I presume), and no login pods.

I was able to unlock the screen by typing my password blindly.

Feedback http://feedback/#/Report/73196604348

Could there be a difference between lid-close/open sleep vs. lid-open timeout sleep?

One other thought: Is it possible that some part of screen lock involves chrome sending a mojo message to ash, which then races with some other part of the lock/sleep process that either uses posted tasks or talks to dbus?

Chrome logs[1] seem fine, but there is a display reconfiguration. I'm not sure if that's typical procedure - I'll check tomorrow.

I'm assuming you were able to login by blindly typing your password?

1: https://paste.googleplex.com/4753384867364864

There were a lot of these messages in the logs as well (outside of just the lock screen section):

  [23106:23106:0914/175112.584668:WARNING:render_frame_host_impl.cc(2602)] OnDidStopLoading was called twice.

If you were not able to login via keyboard I could imagine login loading being stopped which would result in the blank UI - but since you could login I assume it finished successfully.

There recently was an issue like this (see issue 764190).
So if there are errors like:

:ERROR:gl_image_native_pixmap.cc(240)] Failed to flush rendering

it's it.

Unfortunately I don't see any log messages along those lines

I believe this was due to a Chrome bug which was fixed already.
Alemate@ was looking into it a few days ago. 

See #10 - #11.

There are some CONSOLE:ERROR messages in the logs which I believe are harmless, but I've uploaded [1] to fix the setOverlayColors one. Maybe 99% of the time the error message is harmless but 1% it causes this failure?

If that doesn't fix the issue then I think it is unrelated to login and a failure of some other component.

1: https://chromium-review.googlesource.com/c/chromium/src/+/669397

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9c2e2f0e0dfe002eb0a1325c100ffbe2dd0de21d

commit 9c2e2f0e0dfe002eb0a1325c100ffbe2dd0de21d
Author: Jacob Dufault <jdufault@google.com>
Date: Fri Sep 15 21:12:34 2017

cros: Defer setOverlayColors call as login/lock may not be loaded yet.

Bug:  764584 
Change-Id: I359240427c6be20a2576142a7caf8cc12d897edc
Reviewed-on: https://chromium-review.googlesource.com/669397
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502373}
[modify] https://crrev.com/9c2e2f0e0dfe002eb0a1325c100ffbe2dd0de21d/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

This bug requires manual review: M62 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

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

Approving merge to M61 and M62. Please merge and validate on M62 prior to merge on M61.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a3e2ea1b05706bd91ed6d902ebb4541891d86ed3

commit a3e2ea1b05706bd91ed6d902ebb4541891d86ed3
Author: Jacob Dufault <jdufault@google.com>
Date: Mon Sep 18 18:04:36 2017

cros: Defer setOverlayColors call as login/lock may not be loaded yet.

TBR=jdufault@google.com

(cherry picked from commit 9c2e2f0e0dfe002eb0a1325c100ffbe2dd0de21d)

Bug:  764584 
Change-Id: I359240427c6be20a2576142a7caf8cc12d897edc
Reviewed-on: https://chromium-review.googlesource.com/669397
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#502373}
Reviewed-on: https://chromium-review.googlesource.com/671450
Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Cr-Commit-Position: refs/branch-heads/3202@{#296}
Cr-Branched-From: fa6a5d87adff761bc16afc5498c3f5944c1daa68-refs/heads/master@{#499098}
[modify] https://crrev.com/a3e2ea1b05706bd91ed6d902ebb4541891d86ed3/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/569555e5ec7275c46473559f0a11a141d7668d5b

commit 569555e5ec7275c46473559f0a11a141d7668d5b
Author: Jacob Dufault <jdufault@google.com>
Date: Thu Sep 21 19:04:00 2017

cros: Defer setOverlayColors call as login/lock may not be loaded yet.

TBR=jdufault@google.com

(cherry picked from commit 9c2e2f0e0dfe002eb0a1325c100ffbe2dd0de21d)

Bug:  764584 
Change-Id: I359240427c6be20a2576142a7caf8cc12d897edc
Reviewed-on: https://chromium-review.googlesource.com/669397
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#502373}
Reviewed-on: https://chromium-review.googlesource.com/677475
Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#1257}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/569555e5ec7275c46473559f0a11a141d7668d5b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

I suspect this is a duplicate of or related to  issue 767680 .

This also seems like another case of  issue 758820  (busted GPU rasterization)