Also affects ANGLE CQ
https://build.chromium.org/p/tryserver.chromium.angle/builders/win_angle_x64_dbg_ng/builds/1537

It looks to me like the test's occasionally failing to create one of its contexts.

I wonder whether this could be related to cwallez's observation that we seem to be running out of GPU resources while running the WebGL 2.0 conformance tests. All resources allocated by contexts from earlier web pages are supposed to be eagerly deallocated upon page navigation, but if that mechanism has been broken then that might explain the inability to allocate new contexts.

Improving logging and marking flaky in https://codereview.chromium.org/2152283004 .

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fe47448d071d22a0cf1d636e00c8c5808168b853

commit fe47448d071d22a0cf1d636e00c8c5808168b853
Author: kbr <kbr@chromium.org>
Date: Sat Jul 16 02:01:13 2016

Abort ContextLost.WebGLContextLostFromQuantity if context creation fails.

Mark the test flaky on Win Debug (can't identify this separately from
Win x64 Debug). Add better logging.

BUG=628697
CQ_INCLUDE_TRYBOTS=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

Review-Url: https://codereview.chromium.org/2152283004
Cr-Commit-Position: refs/heads/master@{#405919}

[modify] https://crrev.com/fe47448d071d22a0cf1d636e00c8c5808168b853/content/test/data/gpu/webgl.html
[modify] https://crrev.com/fe47448d071d22a0cf1d636e00c8c5808168b853/content/test/gpu/gpu_tests/context_lost.py
[modify] https://crrev.com/fe47448d071d22a0cf1d636e00c8c5808168b853/content/test/gpu/gpu_tests/context_lost_expectations.py

Still flakily timing out after that suppression:
https://build.chromium.org/p/chromium.gpu.fyi/builders/Win7%20x64%20Debug%20%28NVIDIA%29/builds/4720

Skipping it on this configuration.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/53a9cf6f5d28c640f3cace7eb9b11d9fa7aa709e

commit 53a9cf6f5d28c640f3cace7eb9b11d9fa7aa709e
Author: kbr <kbr@chromium.org>
Date: Mon Jul 18 20:30:54 2016

Skip ContextLost.WebGLContextLostFromQuantity on Win Debug.

The flaky suppression didn't work.

BUG=628697
CQ_INCLUDE_TRYBOTS=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
TBR=zmo@chromium.org
NOTRY=true

Review-Url: https://codereview.chromium.org/2159983002
Cr-Commit-Position: refs/heads/master@{#406082}

[modify] https://crrev.com/53a9cf6f5d28c640f3cace7eb9b11d9fa7aa709e/content/test/gpu/gpu_tests/context_lost_expectations.py

Downgrading now that the suppression is in place.