Split out from bug 838504#6:

Another failing build: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_chromium_rel_ng/84965

Swarming logs: https://chromium-swarm.appspot.com/task?id=3d40d4478598de10&refresh=10&show_raw=1

[17966:17966:0503/145842.207069:ERROR:sandbox_linux.cc(378)] InitializeSandbox() called with multiple threads in process gpu-process.
  	[17937:17937:0503/145842.211004:ERROR:gpu_process_transport_factory.cc(664)] Switching to software compositing.
  	[17937:17937:0503/145842.211136:ERROR:gpu_process_transport_factory.cc(1012)] Lost UI shared context.
  	[1:9:0503/145842.263932:ERROR:command_buffer_proxy_impl.cc(133)] ContextResult::kTransientFailure: Failed to send GpuChannelMsg_CreateCommandBuffer.
  	[1:9:0503/145842.264081:ERROR:context_provider_command_buffer.cc(235)] GpuChannelHost failed to create command buffer.
  	[1:1:0503/145857.387624:ERROR:canvas_rendering_context_host.h(67)] Not implemented reached in virtual void blink::CanvasRenderingContextHost::RegisterContextToDispatch(blink::CanvasRenderingContext *)
  	[1:9:0503/145905.898970:FATAL:scoped_web_input_event_with_latency_info.cc(28)] Check failed: other.latency_.trace_id() > latency_.trace_id() (543 vs. 543)
  	#0 0x55db803e662c base::debug::StackTrace::StackTrace()
  	#1 0x55db8034860b logging::LogMessage::~LogMessage()
  	#2 0x55db8482f276 content::ScopedWebInputEventWithLatencyInfo::CoalesceWith()
  	#3 0x55db8482df0d content::QueuedWebInputEvent::FilterNewEvent()
  	#4 0x55db8482ef81 content::MainThreadEventQueueTaskList::Queue()
  	#5 0x55db8482cc89 content::MainThreadEventQueue::QueueEvent()
  	#6 0x55db8482cb38 content::MainThreadEventQueue::HandleEvent()
  	#7 0x55db8483111e content::WidgetInputHandlerManager::DidHandleInputEventAndOverscroll()
  	#8 0x55db84833446 _ZN4base8internal13FunctorTraitsIMN7content25WidgetInputHandlerManagerEFvNS_12OnceCallbackIFvNS2_19InputEventAckSourceERKN2ui11LatencyInfoENS2_18InputEventAckStateERKNS_8OptionalINS6_19DidOverscrollParamsEEERKNSB_IN2cc11TouchActionEEEEEENS6_17InputHandlerProxy16EventDispositionENSt3__110unique_ptrIN5blink13WebInputEventENS6_20WebInputEventDeleterEEES9_NSQ_ISC_NSP_14default_deleteISC_EEEEEvE6InvokeISZ_13scoped_refptrIS3_EJSM_SO_SU_S9_SX_EEEvT_OT0_DpOT1_
  	#9 0x55db84833344 _ZN4base8internal7InvokerINS0_9BindStateIMN7content25WidgetInputHandlerManagerEFvNS_12OnceCallbackIFvNS3_19InputEventAckSourceERKN2ui11LatencyInfoENS3_18InputEventAckStateERKNS_8OptionalINS7_19DidOverscrollParamsEEERKNSC_IN2cc11TouchActionEEEEEENS7_17InputHandlerProxy16EventDispositionENSt3__110unique_ptrIN5blink13WebInputEventENS7_20WebInputEventDeleterEEESA_NSR_ISD_NSQ_14default_deleteISD_EEEEEJ13scoped_refptrIS4_ESN_EEEFvSP_SV_SA_SY_EE7RunOnceEPNS0_13BindStateBaseESP_OSV_SA_OSY_
  	#10 0x55db7e406309 ui::EventWithCallback::RunCallbacks()
  	#11 0x55db7e40762e ui::InputHandlerProxy::DispatchSingleInputEvent()
  	#12 0x55db7e4076e6 ui::InputHandlerProxy::DispatchQueuedInputEvents()
  	#13 0x55db813a5a44 cc::LayerTreeHostImpl::WillBeginImplFrame()
  	#14 0x55db81442a53 cc::ProxyImpl::WillBeginImplFrame()
  	#15 0x55db8144e40d cc::Scheduler::BeginImplFrame()
  	#16 0x55db8144daf1 cc::Scheduler::BeginImplFrameWithDeadline()
  	#17 0x55db8144d204 cc::Scheduler::OnBeginFrameDerivedImpl()
  	#18 0x55db8145a692 viz::BeginFrameObserverBase::OnBeginFrame()
  	#19 0x55db8145d439 viz::ExternalBeginFrameSource::OnBeginFrame()
  	#20 0x55db81af3b90 viz::ClientLayerTreeFrameSink::OnBeginFrame()
  	#21 0x55db7e246c5c viz::mojom::CompositorFrameSinkClientStubDispatch::Accept()
  	#22 0x55db809d2d22 mojo::InterfaceEndpointClient::HandleValidatedMessage()
  	#23 0x55db809d28c6 mojo::FilterChain::Accept()
  	#24 0x55db809d41d2 mojo::InterfaceEndpointClient::HandleIncomingMessage()
  	#25 0x55db809db7fd mojo::internal::MultiplexRouter::ProcessIncomingMessage()
  	#26 0x55db809dabc0 mojo::internal::MultiplexRouter::Accept()
  	#27 0x55db809d28c6 mojo::FilterChain::Accept()
  	#28 0x55db809d01bb mojo::Connector::ReadSingleMessage()
  	#29 0x55db809d0c54 mojo::Connector::ReadAllAvailableMessages()
  	#30 0x55db809d0ab6 mojo::Connector::OnHandleReadyInternal()
  	#31 0x55db7e3a5984 mojo::SimpleWatcher::DiscardReadyState()
  	#32 0x55db809ca3b5 mojo::SimpleWatcher::OnHandleReady()
  	#33 0x55db809ca93e _ZN4base8internal7InvokerINS0_9BindStateIMN4mojo13SimpleWatcherEFvijRKNS3_18HandleSignalsStateEEJNS_7WeakPtrIS4_EEijS5_EEEFvvEE7RunImplIRKS9_RKNSt3__15tupleIJSB_ijS5_EEEJLm0ELm1ELm2ELm3EEEEvOT_OT0_NSI_16integer_sequenceImJXspT1_EEEE
  	#34 0x55db8032e610 base::debug::TaskAnnotator::RunTask()
  	#35 0x55db7fdd1fc5 blink::scheduler::internal::ThreadControllerImpl::DoWork()
  	#36 0x55db7df6ba28 _ZN4base8internal7InvokerINS0_9BindStateIMN5media26AudioDebugRecordingManagerEFvjEJNS_7WeakPtrIS4_EEjEEEFvvEE7RunOnceEPNS0_13BindStateBaseE
  	#37 0x55db8032e610 base::debug::TaskAnnotator::RunTask()
  	#38 0x55db803511f6 base::internal::IncomingTaskQueue::RunTask()
  	#39 0x55db8034f847 base::MessageLoop::RunTask()
  	#40 0x55db8034fc5a base::MessageLoop::DeferOrRunPendingTask()
  	#41 0x55db8034feee base::MessageLoop::DoWork()
  	#42 0x55db80354576 base::MessagePumpDefault::Run()
  	#43 0x55db8034f171 base::MessageLoop::Run()
  	#44 0x55db8037bc96 base::RunLoop::Run()
  	#45 0x55db803ad0ba base::Thread::Run()
  	#46 0x55db803ad40f base::Thread::ThreadMain()
  	#47 0x55db803f9fdf base::(anonymous namespace)::ThreadFunc()
  	#48 0x7f3324528184 start_thread
  	#49 0x7f331e98303d clone
  	
  	[1:1:0503/145906.385223:ERROR:canvas_rendering_context_host.h(67)] Not implemented reached in virtual void blink::CanvasRenderingContextHost::RegisterContextToDispatch(blink::CanvasRenderingContext *)

  [  FAILED  ] system_health.memory_desktop/browse:news:reddit@{'case': 'browse', 'group': 'news'} (40092 ms)