Seen in this build:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Debug%20(NVIDIA)/50

This Swarming job:
https://chromium-swarm.appspot.com/task?id=3d7df5167d76ee10&refresh=10&show_raw=1

This test:
WebglConformance_conformance_textures_image_bitmap_from_video_tex_2d_luminance_alpha_luminance_alpha_unsigned_byte

of webgl_conformance_tests.

Stack trace:

[1:30:0515/115753.246874:FATAL:video_frame_submitter.cc(178)] Check failed: compositor_frame_sink_. 
#0 0x7f35a47df1ed base::debug::StackTrace::StackTrace()
#1 0x7f35a450862c base::debug::StackTrace::StackTrace()
#2 0x7f35a45785ca logging::LogMessage::~LogMessage()
#3 0x7f358bc22c2a blink::VideoFrameSubmitter::SubmitFrame()
#4 0x7f358bc25fc1 _ZN4base8internal13FunctorTraitsIMN5blink19VideoFrameSubmitterEFvN3viz13BeginFrameAckE13scoped_refptrIN5media10VideoFrameEEEvE6InvokeISB_NS_7WeakPtrIS3_EEJS5_S9_EEEvT_OT0_DpOT1_
#5 0x7f358bc25eb5 _ZN4base8internal12InvokeHelperILb1EvE8MakeItSoIMN5blink19VideoFrameSubmitterEFvN3viz13BeginFrameAckE13scoped_refptrIN5media10VideoFrameEEENS_7WeakPtrIS5_EEJS7_SB_EEEvOT_OT0_DpOT1_
#6 0x7f358bc25e1d _ZN4base8internal7InvokerINS0_9BindStateIMN5blink19VideoFrameSubmitterEFvN3viz13BeginFrameAckE13scoped_refptrIN5media10VideoFrameEEEJNS_7WeakPtrIS4_EES6_SA_EEEFvvEE7RunImplISC_NSt3__15tupleIJSE_S6_SA_EEEJLm0ELm1ELm2EEEEvOT_OT0_NSJ_16integer_sequenceImJXspT1_EEEE
#7 0x7f358bc25cf9 _ZN4base8internal7InvokerINS0_9BindStateIMN5blink19VideoFrameSubmitterEFvN3viz13BeginFrameAckE13scoped_refptrIN5media10VideoFrameEEEJNS_7WeakPtrIS4_EES6_SA_EEEFvvEE7RunOnceEPNS0_13BindStateBaseE
#8 0x7f35a44b71fe _ZNO4base12OnceCallbackIFvvEE3RunEv
#9 0x7f35a4509af2 base::debug::TaskAnnotator::RunTask()
#10 0x7f35a4597bc9 base::internal::IncomingTaskQueue::RunTask()
#11 0x7f35a45a0cb7 base::MessageLoop::RunTask()
#12 0x7f35a45a0f28 base::MessageLoop::DeferOrRunPendingTask()
#13 0x7f35a45a1259 base::MessageLoop::DoWork()
#14 0x7f35a45a4887 base::MessagePumpDefault::Run()
#15 0x7f35a45a04ab base::MessageLoop::Run()
#16 0x7f35a464a06d base::RunLoop::Run()
#17 0x7f35a46fdb28 base::Thread::Run()
#18 0x7f35a46fe6e8 base::Thread::ThreadMain()
#19 0x7f35a48140ed base::(anonymous namespace)::ThreadFunc()
#20 0x7f35a4a7f184 start_thread
#21 0x7f3583d3537d clone

Not sure how often this is happening. It looks pretty rare.

Chris or Fady, is this related to the changes ongoing in  Issue 837030 ? If so could you please take this and prioritize it? I'm not sure whether this will reproduce reliably with a local Linux debug build running the test over and over. Instructions on running these tests locally are here:

https://chromium.googlesource.com/chromium/src/+/master/docs/gpu/gpu_testing.md#Running-the-GPU-Tests-Locally

Thanks.