Roll ANGLE from 3ae1f33606d6 to 81af4bc6b3ae (2 revisions)

https://chromium.googlesource.com/angle/angle.git/+log/3ae1f33606d6..81af4bc6b3ae

2021-09-04 angle-autoroll@skia-public.iam.gserviceaccount.com Roll Chromium from 8ef1e454 to 6261dad8 (60 revisions)
2021-09-04 zequanwu@google.com Revert "Skip validation of stderr in TestSuiteTest.RunFlakyTests"

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/angle-chromium-autoroll
Please CC geofflang@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in ANGLE: https://bugs.chromium.org/p/angleproject/issues/entry
To file a bug in Chromium: https://bugs.chromium.org/p/chromium/issues/entry

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

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-asan;luci.chromium.try:win_optional_gpu_tests_rel;luci.chromium.try:linux-swangle-try-x64;luci.chromium.try:win-swangle-try-x86
Bug: chromium:1234124
Tbr: geofflang@google.com
Change-Id: I5299152674793f8135bd69a6d654ccbfb6c89138
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3142531
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#918366}