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.

Just some observations:
The test passes on Windows, OpenGL and D3D11 (Public driver 416.34)
The test fails on Android Shield TV public 7.2.2
We worked on similar issue for OpenGL in internal bug 1758777, fixed late 2016.

The failure is probably with OpenGL ES context.

The failing shader is like:
#version 300 es
out mediump vec4 _ucolor;
bool _uhasRan = false;
mediump float[2] _ufunctionReturnArray(){
(_uhasRan = true);
return float[2](2.0, 1.0);
}
void main(){
mediump float _uc = _ufunctionReturnArray()[0];
(_ucolor = ((((_uc == 2.0) && _uhasRan)) ? (vec4(0.0, 1.0, 0.0, 1.0)) : (vec4(1.0, 0.0, 0.0, 1.0))));
}

mediump float _uc = _ufunctionReturnArray()[0]; seems to fail