You are probably looking for a change made after 515035 (known good), but no later than 515036 (first known bad).

CHANGE-LOG URL:

The script might not always return single CL as suspect as some perf builds might get missing due to failure.

https://chromium.googlesource.com/chromium/src/+log/cdf40eef972eea49a3764fb9c6b59af908fdeecb..1202f66559ca7e37f643a691cac72144ab60493f

Suspect: https://chromium.googlesource.com/chromium/src/+/1202f66559ca7e37f643a691cac72144ab60493f

@zmo: Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thank You!

Adding Release blocker for this issue.Please undo if not the case.

Thank You!

It's working for me on ToT build on Linux.

Let me try to reproduce on Mac where we don't have SwiftShader.

Can't reproduce on my Mac station with ToT.

Whoever can reproduce this, please provide the about:gpu page content.

Also tested on my Macbook Pro (Retina, Middle 2015). I can't reproduce this.

W.R.T to comment #4,6,7.

Re-bisected the above issue and getting the same suspect.

Suspect: https://chromium.googlesource.com/chromium/src/+/1202f66559ca7e37f643a691cac72144ab60493f

Kindly note: The above issue is ONLY MAC(10.12.6, 10.13.2) specific and is not reproducible on WIN(7,8,10) and LINUX(14.04 LTS) OS.

You will have to provide which Mac you reproduce this (about:gpu page content). I tried two Mac and I can't reproduce this issue with ToT build.

Below attached is the gpu data

Deleted: chrome:::gpu.rtf 51.9 KB

chrome:::gpu.rtf 51.9 KB Download

Sorry I don't know how to open the file attachment-311608.dat

Please attach as plain txt file or html file.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/630842eac3832f11f04f626774943de31b1ce35a

commit 630842eac3832f11f04f626774943de31b1ce35a
Author: Zhenyao Mo <zmo@chromium.org>
Date: Sat Nov 11 01:27:48 2017

Add pixel tests for --disable-gpu mode.

On Win/Linux, we will fallback to rendering with SwiftShader.
On other platforms, we will fallback to software rendering with no gpu process.

BUG= 783069 
TEST=the added tests
R=kbr@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I9a60c71fba04ebdb46d92a5a0442a75f4f236e90
Reviewed-on: https://chromium-review.googlesource.com/764000
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515780}
[modify] https://crrev.com/630842eac3832f11f04f626774943de31b1ce35a/content/test/gpu/gpu_tests/pixel_expectations.py
[modify] https://crrev.com/630842eac3832f11f04f626774943de31b1ce35a/content/test/gpu/gpu_tests/pixel_integration_test.py
[modify] https://crrev.com/630842eac3832f11f04f626774943de31b1ce35a/content/test/gpu/gpu_tests/pixel_test_pages.py

Update : 
Retested above issue using latest Mac #64.0.3265.0 build on Mac(10.12.6) OS and issue is still reproducible. Please review an attached screen cast.

Thank you!

Deleted: Current_behaviour.mov 4.9 MB

Current_behaviour.mov 4.9 MB Download

Reporter: please don't remove the Needs-Feedback label unless you provide the requested feedback (about:gpu page content in a .txt or .html format).

Basically I can't reproduce the issue in two Mac machines I have, so I really need to know on which platform you can reproduce this. Otherwise I can't make progress.

Hi Developer, 

Sorry for delay.
Below attached is your about://gpu content file.

Try disabling hardware acceleration step twice to reproduce the steps if not seen on first instance.

Deleted: GPU.txt 17.8 KB

GPU.txt 17.8 KB View Download

Thank you. Yes, I can reproduce this on MacBook Air with Intel HD 4000.

I suspect this is the same issue as  crbug.com/783728 . Need to verify

Interestingly, I can't reproduce the issue with the same version Chromium build (#515780), but I can reproduce with Canary (#515780). Might have something to do with Finch experiments.

Confirmed. This is the same root cause as  crbug.com/783728 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/69f6991a1a338e43dc51f2f40f77b47cdc486c2a

commit 69f6991a1a338e43dc51f2f40f77b47cdc486c2a
Author: Zhenyao Mo <zmo@chromium.org>
Date: Thu Nov 16 21:23:45 2017

Update test expectations for newly added Pixel tests.

BUG= 783069 
TEST=GPU bots
R=kbr@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: If14091cbaa75d941a88c28f7a3aa7baed3d7e0e9
Reviewed-on: https://chromium-review.googlesource.com/767115
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517195}
[modify] https://crrev.com/69f6991a1a338e43dc51f2f40f77b47cdc486c2a/content/test/gpu/gpu_tests/gpu_integration_test.py
[modify] https://crrev.com/69f6991a1a338e43dc51f2f40f77b47cdc486c2a/content/test/gpu/gpu_tests/pixel_expectations.py