More specifically, it was disabled on all platforms here:
https://chromium-review.googlesource.com/1169959

Olli, was this expected to fail everywhere, or only on certain platforms? It was hard to tell from the history of that CL whether it passed or failed on AMD or Intel GPUs. (It looks like there were some catastrophic test failures – fortunately cleaned up since.)

It was expected to fail only on NVIDIA, and passes at least on my Intel machine, but I haven't tested it on AMD.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/539ef7dd7cb70fc0fa684c44c0bfce18ced47e61

commit 539ef7dd7cb70fc0fa684c44c0bfce18ced47e61
Author: Corentin Wallez <cwallez@chromium.org>
Date: Tue Nov 13 17:08:12 2018

Add back some WebGL test expectations

A lot of expectations were removed but some of them were still
necessary, this adds them back.

TBR=kbr@chromium.org
BUG= chromium:693135 
BUG=chromium:772651
BUG= chromium:798117 
BUG= chromium:874620 
BUG=chromium:887241

Change-Id: Ib3bccdf2ff48a28a8f0a3ce428239980a58c5266
Reviewed-on: https://chromium-review.googlesource.com/c/1333650
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607626}
[modify] https://crrev.com/539ef7dd7cb70fc0fa684c44c0bfce18ced47e61/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
[modify] https://crrev.com/539ef7dd7cb70fc0fa684c44c0bfce18ced47e61/content/test/gpu/gpu_tests/webgl_conformance_expectations.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6829aab5f8698d265317183be5e6e50e4551edf9

commit 6829aab5f8698d265317183be5e6e50e4551edf9
Author: James Darpinian <jdarpinian@chromium.org>
Date: Thu Nov 29 00:44:19 2018

Add suppressions for Pixel 2 and Nvidia Shield TV

We're not yet enabling the tests to run on the waterfall due to lack
of hardware, but the tests currently pass with these suppressions.

Bug: 709351,  809233 , 830046, 850257,  874620 
Bug: 905006, 906735, 906735, 906737, 906739
Bug: 906740, 906742,  906743 , 906745, 906752
Change-Id: I7362e52e9df8ae8f591d11a4a1e272fa2b81b0b6
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
Reviewed-on: https://chromium-review.googlesource.com/c/1340275
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: James Darpinian <jdarpinian@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611965}
[modify] https://crrev.com/6829aab5f8698d265317183be5e6e50e4551edf9/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

Adding James Helferty (jhelferty@nvidia.com) to CC for WebGL conformance issues on Nvidia GPUs.

I think this bug originated from issue 871434.
If I understand correctly we have fixed this but I'm unsure if the driver is out. I'll check.

Thanks, let us know what driver version has the fix.

Taking the liberty of marking as duplicate of 871434