All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=822235

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=c33f09611a25fac1b57cdb27620829feb7237564b9da4f98e8e08d9487ed988e


Bot(s) for this bug's original alert(s):

chromium-rel-win7-gpu-nvidia

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/12cbb811440000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/17d6e7a1440000

📍 Found significant differences after each of 4 commits.
https://pinpoint-dot-chromeperf.appspot.com/job/12cbb811440000

gpu_test_expectations: Fix test for API overlap by lucferron@chromium.org
https://chromium.googlesource.com/angle/angle/+/7c9492eb2494b4831a0f8048fad5ef4519c87afe

Run clang-format on State.cpp by lfy@google.com
https://chromium.googlesource.com/angle/angle/+/54ef3ad44c8c42610f7fee84c96f06484f0f0f58

Remove histogram validatiaon. by bcwhite@chromium.org
https://chromium.googlesource.com/chromium/src/+/caef6e1e17dc247e0a7c8643382abc10a59fbc15

GLES1: state: Define / initialize GLES1-specific states by lfy@google.com
https://chromium.googlesource.com/angle/angle/+/dbb9c53462ef82f0a1a8056052d0583f0e7f2467

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

📍 Found significant differences after each of 3 commits.
https://pinpoint-dot-chromeperf.appspot.com/job/17d6e7a1440000

Framebuffer: Handle errors in checkStatus. by jmadill@chromium.org
https://chromium.googlesource.com/angle/angle/+/e98b1b5d41bf7ca2ecc43c75354c47e6756374fa

Remove histogram validatiaon. by bcwhite@chromium.org
https://chromium.googlesource.com/chromium/src/+/caef6e1e17dc247e0a7c8643382abc10a59fbc15

GLES1: state: Define / initialize GLES1-specific states by lfy@google.com
https://chromium.googlesource.com/angle/angle/+/dbb9c53462ef82f0a1a8056052d0583f0e7f2467

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

Removing people who could not possibly be implicated.

Simon/dtu, do you know what happened in comment #5? It seems some of the builds failed, and we don't have conclusive results.

Re-link: https://pinpoint-dot-chromeperf.appspot.com/job/12cbb811440000

Pretty sure this is because of my CL: https://chromium-review.googlesource.com/954406 

This would somewhat significantly affect validation speed.

I think what happened is that since we had some build failures, Pinpoint pointed at the first working one after them instead of mentioning it could have happened anywhere in the range.

Seems right, but what exactly was the problem? There was some very tiny error text:

Traceback (most recent call last):
  File "/base/data/home/apps/s~chromeperf/pinpoint:dev-dtu-87b05184.408337895109377504/dashboard/pinpoint/models/quest/execution.py", line 99, in Poll
    self._Poll()
  File "/base/data/home/apps/s~chromeperf/pinpoint:dev-dtu-87b05184.408337895109377504/dashboard/pinpoint/models/quest/find_isolate.py", line 73, in _Poll
    self._CheckBuildStatus()
  File "/base/data/home/apps/s~chromeperf/pinpoint:dev-dtu-87b05184.408337895109377504/dashboard/pinpoint/models/quest/find_isolate.py", line 110, in _CheckBuildStatus
    raise BuildError('Buildbucket says the build completed successfully, '
BuildError: Buildbucket says the build completed successfully, but Pinpoint can't find the isolate hash.

Any idea what's happening there?

Dave, any ideas?

Looks like an issue with Pinpoint's handling of the angle repo. I've filed a bug.
https://github.com/catapult-project/catapult/issues/4348

The following revision refers to this bug:
  https://chromium.googlesource.com/angle/angle/+/427064d2ac0bdd008cc259bb865d9d13cd7eeced

commit 427064d2ac0bdd008cc259bb865d9d13cd7eeced
Author: Jamie Madill <jmadill@chromium.org>
Date: Wed Apr 18 17:48:24 2018

Fix perf regression with checkStatus.

Returning an Error was costing us performance in extra
error checks. This intead uses the Context to process the
Error immediately, and returns a value from isComplete and
checkStatus.

Improves performance in draw call validation.

Bug:  chromium:822235 
Change-Id: I0793fc690e86137425fed593d45083e40aee8db9
Reviewed-on: https://chromium-review.googlesource.com/1011370
Reviewed-by: Luc Ferron <lucferron@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/validationES.h
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/Debug.h
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/State.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/validationES2.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/Context.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/Framebuffer.h
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/validationES3.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/Framebuffer.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/validationES31.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/validationES.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/Debug.cpp
[modify] https://crrev.com/427064d2ac0bdd008cc259bb865d9d13cd7eeced/src/libANGLE/Context.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f75b68260e989a6f9141e96d629e7599929a9a8c

commit f75b68260e989a6f9141e96d629e7599929a9a8c
Author: angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Date: Wed Apr 18 19:57:30 2018

Roll src/third_party/angle/ eb79e337c..427064d2a (8 commits)

https://chromium.googlesource.com/angle/angle.git/+log/eb79e337c9f7..427064d2ac0b

$ git log eb79e337c..427064d2a --date=short --no-merges --format='%ad %ae %s'
2018-04-13 jmadill Fix perf regression with checkStatus.
2018-04-10 courtneygo Vulkan: Add build toggle for validation layers.
2018-04-17 jmadill Optimize ValidateDrawAttribs: Part 2.
2018-04-16 lucferron Vulkan: Use SH_INITIALIZE_UNINITIALIZED_LOCALS in ShaderVk
2018-04-16 lucferron Vulkan: Implement depth_range dirty bit and enable tests
2018-04-16 lucferron Vulkan: Fix the issue with unused attributes / varyings
2018-04-18 lucferron Vulkan: Fix issue in GlslWrapper and maxVaryingVectors calculation (2nd try)
2018-04-13 oetuaho Refactor GL tests to use a shader library

Created with:
  roll-dep src/third_party/angle
BUG= chromium:822235 


The AutoRoll server is located here: https://angle-chromium-roll.skia.org

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.


CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
TBR=jmadill@chromium.org

Change-Id: I99521579232a65d62698e7c4f73aa0b697f219fc
Reviewed-on: https://chromium-review.googlesource.com/1017318
Commit-Queue: angle-chromium-autoroll <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Reviewed-by: angle-chromium-autoroll <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#551792}
[modify] https://crrev.com/f75b68260e989a6f9141e96d629e7599929a9a8c/DEPS

Graphs have recovered.