rockot@ - could you triage and make sure this gets routed to someone who can fix (or disable) this test.

It may be related to my recent changes.

I will take a look.

A revert (https://codereview.chromium.org/2590393002/) has been sent to the CQ.

Detected 8 new flakes for test/step "WebUIMojoTest.EndToEndPing". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyJQsSBUZsYWtlIhpXZWJVSU1vam9UZXN0LkVuZFRvRW5kUGluZww. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

The test is no longer flaky after I reverted my CL.

But I will keep this bug open until I figured out why my CL caused flakiness.

=======================================================================================
This is the call stack:

WebUIMojoTest.EndToEndPing (run #1):
[ RUN      ] WebUIMojoTest.EndToEndPing
Backtrace:
	v8_inspector::InspectedContext::contextId [0x01C105A7+7]
	v8_inspector::V8InspectorImpl::willExecuteScript [0x01C2D2C1+17]
	blink::ThreadDebugger::willExecuteScript [0x033AF23E+46]
	blink::V8ScriptRunner::callFunction [0x02EEDD81+425]
	blink::WebLocalFrameImpl::callFunctionEvenIfScriptDisabled [0x02E85E6C+133]
	content::MojoMainRunner::Call [0x02D3BE33+26]
	content::MojoContextState::Run [0x02D04E80+299]
	base::internal::FunctorTraits<void (__cdecl*)(base::WeakPtr<gin::Runner>,v8::Local<v8::Value>),void>::Invoke<base::WeakPtr<gin::Runner> const &,v8::Local<v8::Value> > [0x02D03FED+34]
	base::internal::Invoker<base::internal::BindState<void (__cdecl*)(base::WeakPtr<gin::Runner>,v8::Local<v8::Value>),base::WeakPtr<gin::Runner> >,void __cdecl(v8::Local<v8::Value>)>::Run [0x02D04D35+21]
	base::internal::RunMixin<base::Callback<bool __cdecl(content::DownloadItemImpl const *),1,1> >::Run [0x01449E9A+32]
	gin::ModuleRegistry::LoadModule [0x03AECADB+75]
	content::MojoContextState::Run [0x02D04DC5+112]
	content::MojoBindingsController::RunScriptsAtDocumentReady [0x02C940DC+42]
	content::RenderFrameImpl::runScriptsAtDocumentReady [0x02C51AA8+125]
	blink::FrameLoaderClientImpl::runScriptsAtDocumentReady [0x02EBA2D0+35]
	blink::FrameLoader::finishedParsing [0x034C1F66+110]
	blink::Document::finishedParsing [0x030F244B+350]
	blink::HTMLDocumentParser::end [0x03301A5A+115]
	base::PlatformThread::CurrentRef [0x022D2A29+9]
	blink::HTMLDocumentParser::pumpPendingSpeculations [0x03303B95+523]
	WTF::Function<void __cdecl(void),1>::operator() [0x02DAE773+100]
	blink::TaskHandle::Runner::run [0x02DAEC13+27]
	base::internal::InvokeHelper<1,void>::MakeItSo<void (__thiscall blink::TaskHandle::Runner::*const &)(blink::TaskHandle const &),base::WeakPtr<blink::TaskHandle::Runner> const &,blink::TaskHandle const &> [0x02DAE537+49]
	base::internal::Invoker<base::internal::BindState<void (__thiscall blink::TaskHandle::Runner::*)(blink::TaskHandle const &),base::WeakPtr<blink::TaskHandle::Runner>,blink::TaskHandle>,void __cdecl(void)>::Run [0x02DAE7D0+23]
	base::debug::TaskAnnotator::RunTask [0x0233F2FF+383]
	blink::scheduler::TaskQueueManager::ProcessTaskFromWorkQueue [0x02E17BBC+955]
	blink::scheduler::TaskQueueManager::DoWork [0x02E1713B+369]
	base::internal::FunctorTraits<void (__thiscall blink::scheduler::TaskQueueManager::*)(base::TimeTicks,bool),void>::Invoke<base::WeakPtr<blink::scheduler::TaskQueueManager> const &,base::TimeTicks const &,bool const &> [0x02E165DC+34]
	base::internal::InvokeHelper<1,void>::MakeItSo<void (__thiscall blink::scheduler::TaskQueueManager::*const &)(base::TimeTicks,bool),base::WeakPtr<blink::scheduler::TaskQueueManager> const &,base::TimeTicks const &,bool const &> [0x02E16622+37]
	base::internal::Invoker<base::internal::BindState<void (__thiscall blink::scheduler::TaskQueueManager::*)(base::TimeTicks,bool),base::WeakPtr<blink::scheduler::TaskQueueManager>,base::TimeTicks,bool>,void __cdecl(void)>::RunImpl<void (__thiscall blink::sc [0x02E1663E+23]
	base::internal::Invoker<base::internal::BindState<void (__thiscall blink::scheduler::TaskQueueManager::*)(base::TimeTicks,bool),base::WeakPtr<blink::scheduler::TaskQueueManager>,base::TimeTicks,bool>,void __cdecl(void)>::Run [0x02E17FAB+22]
	base::debug::TaskAnnotator::RunTask [0x0233F2FF+383]
	base::MessageLoop::RunTask [0x022D5DBC+1228]
	base::MessageLoop::DoWork [0x022D4C73+611]
	base::MessagePumpDefault::Run [0x0234011B+219]
	base::MessageLoop::RunHandler [0x022D58E1+305]
	base::RunLoop::Run [0x022CCA04+132]
	content::RendererMain [0x02C70506+486]
	content::RunNamedProcessTypeMain [0x01D12A0C+206]
	content::ContentMainRunnerImpl::Run [0x01D1290D+280]
	content::ContentMain [0x01D11DD7+35]
	content::LaunchTests [0x020C67BB+560]
	main [0x03AD2F66+48]
	__scrt_common_main_seh [0x03A9960C+249] (f:\ddctools\crtcstartup\src\startup\exe_common.inl:253)
	BaseThreadInitThunk [0x76D9338A+18]
	RtlInitializeExceptionChain [0x77B19902+99]
	RtlInitializeExceptionChain [0x77B198D5+54]

WebUIMojoTest.EndToEndPing (run #2):
[ RUN      ] WebUIMojoTest.EndToEndPing