I faced this on ChromeOS OOBE screen:

[1:5:0323/211223.735306:FATAL:input_handler_proxy.cc(799)] Check failed: !expect_scroll_update_end_. 
#0 0x5bd9f07eb6dd base::debug::StackTrace::StackTrace()
#1 0x5bd9f07ea3ac base::debug::StackTrace::StackTrace()
#2 0x5bd9f08380df logging::LogMessage::~LogMessage()
#3 0x5bd9eb8fc61d ui::InputHandlerProxy::HandleGestureScrollBegin()
#4 0x5bd9eb8faf79 ui::InputHandlerProxy::HandleInputEvent()
#5 0x5bd9eb8fac41 ui::InputHandlerProxy::DispatchSingleInputEvent()
#6 0x5bd9eb8f9c9c ui::InputHandlerProxy::HandleInputEventWithLatencyInfo()
#7 0x5bd9f9fbc3b2 content::InputHandlerManager::HandleInputEvent()
#8 0x5bd9f9fb3f13 content::InputEventFilter::ForwardToHandler()
#9 0x5bd9f9b559dc _ZN4base8internal13FunctorTraitsIMN13CastVideoSink9DelivererEFvRK13scoped_refptrIN5media10VideoFrameEENS_9TimeTicksEEvE6InvokeIRKS4_IS3_EJS9_SA_EEEvSC_OT_DpOT0_
#10 0x5bd9f9fb890b _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIRKMN7content16InputEventFilterEFvRKN3IPC7MessageENS_9TimeTicksEEJRK13scoped_refptrIS5_ES9_RKSA_EEEvOT_DpOT0_
#11 0x5bd9f9fb8884 _ZN4base8internal7InvokerINS0_9BindStateIMN7content16InputEventFilterEFvRKN3IPC7MessageENS_9TimeTicksEEJ13scoped_refptrIS4_ES6_S9_EEEFvvEE7RunImplIRKSB_RKSt5tupleIJSD_S6_S9_EEJLm0ELm1ELm2EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEE
#12 0x5bd9f9fb875c _ZN4base8internal7InvokerINS0_9BindStateIMN7content16InputEventFilterEFvRKN3IPC7MessageENS_9TimeTicksEEJ13scoped_refptrIS4_ES6_S9_EEEFvvEE3RunEPNS0_13BindStateBaseE
#13 0x5bd9eb3d4829 _ZNO4base8CallbackIFvvELNS_8internal8CopyModeE0ELNS2_10RepeatModeE0EE3RunEv
#14 0x5bd9f0a44712 base::debug::TaskAnnotator::RunTask()
#15 0x5bd9f085aacd base::MessageLoop::RunTask()
#16 0x5bd9f085ad74 base::MessageLoop::DeferOrRunPendingTask()
#17 0x5bd9f085b0a0 base::MessageLoop::DoWork()
#18 0x5bd9f0875bc8 base::MessagePumpDefault::Run()
#19 0x5bd9f085a627 base::MessageLoop::RunHandler()
#20 0x5bd9f08fc76a base::RunLoop::Run()
#21 0x5bd9f097c624 base::Thread::Run()
#22 0x5bd9f097ce8a base::Thread::ThreadMain()
#23 0x5bd9f096483c base::(anonymous namespace)::ThreadFunc()
#24 0x73c9cfc3c558 <unknown>
#25 0x73c9ce96a08d clone


I don't have a reproducible scenario, though.