A couple of my CLs were failing on this trybot e.g. https://chromium-review.googlesource.com/c/550887/

The last build to fail this way AFAICT is https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_optional_gpu_tests_rel/builds/10590 which was at Tue Jun 27 20:29:31 2017

You can find more by searching for this failure reason: "Failed steps failed webgl2_conformance_tests on nvidia gpu on linux (with patch) on ubuntu failed webgl2_conformance_tests on nvidia gpu on linux failed failure reason"

Swarming output tail from one of the failed tasks (https://chromium-swarm.appspot.com/task?id=37057cae24bb9d10&refresh=10&show_raw=1)

[3949:3971:0627/200859.906074:WARNING:simple_synchronous_entry.cc(1102)] Could not open platform files for entry.
[3949:3990:0627/200859.946662:FATAL:bus.cc(832)] Check failed: origin_task_runner_.get(). 
#0 0x7f3c6c57f8c7 base::debug::StackTrace::StackTrace()
#1 0x7f3c6c59984d logging::LogMessage::~LogMessage()
#2 0x7f3c6d87ce01 dbus::Bus::GetOriginTaskRunner()
#3 0x7f3c6d88e897 dbus::ObjectProxy::CallMethodWithErrorCallback()
#4 0x7f3c6d88e362 dbus::ObjectProxy::CallMethod()
#5 0x7f3c6e0ae8bc device::PowerSaveBlocker::Delegate::ApplyBlock()
#6 0x7f3c6a96e4b3 _ZN4base8internal7InvokerINS0_9BindStateIMN7content21EmbeddedServiceRunner15InstanceManagerEFvvEJ13scoped_refptrIS5_EEEEFvvEE3RunEPNS0_13BindStateBaseE
#7 0x7f3c6a8da7c1 _ZNO4base8CallbackIFvvELNS_8internal8CopyModeE1ELNS2_10RepeatModeE1EE3RunEv
#8 0x7f3c6c631453 base::debug::TaskAnnotator::RunTask()
#9 0x7f3c6c5e8636 base::internal::TaskTracker::PerformRunTask()
#10 0x7f3c6c5e8cd0 base::internal::TaskTrackerPosix::PerformRunTask()
#11 0x7f3c6c5e7e3c base::internal::TaskTracker::RunNextTask()
#12 0x7f3c6c63c2fe base::internal::SchedulerWorker::Thread::ThreadMain()
#13 0x7f3c6c5f0a1c base::(anonymous namespace)::ThreadFunc()
#14 0x7f3c6987e182 start_thread
#15 0x7f3c6359147d clone

No path to crashpad_database_util found
No minidump found via crashpad_database_util
Found minidump via globbing in minidump dir
Minidump found: /b/swarm_slave/w/itaNdC6J/tmp6PkEL8/b8ef1dbb-9ddd-4dc2-be8c8ca3-fa5eb2b8.dmp
Uploading /b/swarm_slave/w/itaNdC6J/tmp6PkEL8/b8ef1dbb-9ddd-4dc2-be8c8ca3-fa5eb2b8.dmp to gs://chrome-telemetry-output/minidump-2017-06-27_20-09-00-727530.dmp
Dumping breakpad symbols.

kbr@ assigned to you because I can't assign to the pixel wrangler nicolascapens@ (they don't seem to have a chromium.org account and using a google.com account doesn't work because it's not registered with the chromium project)