Example stack:

[ RUN      ] FrameIdTest.RunAsyncTest
[5016:6648:0510/144221.913:37432828:ERROR:registration_protocol_win.cc(84)] TransactNamedPipe: The pipe has been ended. (0x6D)
[5016:6648:0510/144221.913:37432828:WARNING:resource_bundle.cc(358)] locale_file_path.empty() for locale 
[5016:6648:0510/144222.054:37432968:ERROR:gpu_process_transport_factory.cc(664)] Switching to software compositing.
[5016:6648:0510/144222.054:37432968:ERROR:gpu_process_transport_factory.cc(1012)] Lost UI shared context.
[5016:9016:0510/144222.308:37433218:ERROR:service_manager_context.cc(250)] Attempting to run unsupported native service: C:\b\s\w\ir\out\Debug_x64\content_renderer.service.exe
[0510/144222.389:ERROR:registration_protocol_win.cc(56)] CreateFile: The system cannot find the file specified. (0x2)
../../headless/test/headless_browser_test.cc(246): error: Failed
Abnormal renderer termination
Stack trace:
Backtrace:
	StackTraceGetter::CurrentStackTrace [0x00007FF733A9B670+80]
	testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop [0x00007FF733ABA20A+90]
	testing::internal::AssertHelper::operator= [0x00007FF733AB9BBA+90]
	headless::HeadlessAsyncDevTooledBrowserTest::RenderProcessExited [0x00007FF733660930+192]
	headless::HeadlessWebContentsImpl::RenderProcessExited [0x00007FF9558EAF05+421]
	content::RenderProcessHostImpl::ProcessDied [0x00007FF93966F5D6+1222]
	content::RenderProcessHostImpl::OnChannelError [0x00007FF939671B53+179]
	IPC::ChannelProxy::Context::OnDispatchError [0x00007FF959D9287D+45]
	??$Invoke@P8Context@ChannelProxy@IPC@@EAAXXZAEBV?$scoped_refptr@VContext@ChannelProxy@IPC@@@@$$V@?$FunctorTraits@P8Context@ChannelProxy@IPC@@EAAXXZX@internal@base@@SAXP8Context@ChannelProxy@IPC@@EAAXXZAEBV?$scoped_refptr@VContext@ChannelProxy@IPC@@@@@Z [0x00007FF959D9A993+67]
	base::internal::InvokeHelper<0,void>::MakeItSo<void (__cdecl IPC::ChannelProxy::Context::*const & __ptr64)(void) __ptr64,scoped_refptr<IPC::ChannelProxy::Context> const & __ptr64> [0x00007FF959D9A8E6+86]
	base::internal::Invoker<base::internal::BindState<void (__cdecl IPC::ChannelProxy::Context::*)(void) __ptr64,scoped_refptr<IPC::ChannelProxy::Context> >,void __cdecl(void)>::RunImpl<void (__cdecl IPC::ChannelProxy::Context::*const & __ptr64)(void) __ptr64 [0x00007FF959D9A869+73]
	base::internal::Invoker<base::internal::BindState<void (__cdecl IPC::ChannelProxy::Context::*)(void) __ptr64,scoped_refptr<IPC::ChannelProxy::Context> >,void __cdecl(void)>::Run [0x00007FF959D9A76C+60]
	base::OnceCallback<void __cdecl(void)>::Run [0x00007FF949293EF1+97]
	base::debug::TaskAnnotator::RunTask [0x00007FF949311CE3+915]
	base::internal::IncomingTaskQueue::RunTask [0x00007FF9493C75D4+212]
	base::MessageLoop::RunTask [0x00007FF9493D2C82+946]
	base::MessageLoop::DeferOrRunPendingTask [0x00007FF9493D3773+83]
	base::MessageLoop::DoWork [0x00007FF9493D3AB4+532]
	base::MessagePumpForUI::DoRunLoop [0x00007FF9493E25FD+77]
	base::MessagePumpWin::Run [0x00007FF9493E17D7+199]
	base::MessageLoop::Run [0x00007FF9493D239C+524]
	base::RunLoop::Run [0x00007FF9494DF0EA+506]
	headless::HeadlessBrowserTest::RunAsynchronousTest [0x00007FF733660280+432]
	headless::HeadlessAsyncDevTooledBrowserTest::RunTest [0x00007FF733660CCF+735]
	headless::FrameIdTest_RunAsyncTest_Test::RunTestOnMainThread [0x00007FF733504DD3+19]
	content::BrowserTestBase::ProxyRunTestOnMainThreadLoop [0x00007FF734CC04AB+811]
	??$Invoke@P8BrowserTestBase@content@@EAAXXZPEAV12@$$V@?$FunctorTraits@P8BrowserTestBase@content@@EAAXXZX@internal@base@@SAXP8BrowserTestBase@content@@EAAXXZ$$QEAPEAV34@@Z [0x00007FF734CC389A+26]
	base::internal::InvokeHelper<0,void>::MakeItSo<void (__cdecl content::BrowserTestBase::*const & __ptr64)(void) __ptr64,content::BrowserTestBase * __ptr64> [0x00007FF734CC3804+52]
	base::internal::Invoker<base::internal::BindState<void (__cdecl content::BrowserTestBase::*)(void) __ptr64,base::internal::UnretainedWrapper<content::BrowserTestBase> >,void __cdecl(void)>::RunImpl<void (__cdecl content::BrowserTestBase::*const & __ptr64) [0x00007FF734CC3798+88]
	base::internal::Invoker<base::internal::BindState<void (__cdecl content::BrowserTestBase::*)(void) __ptr64,base::internal::UnretainedWrapper<content::BrowserTestBase> >,void __cdecl(void)>::Run [0x00007FF734CC368C+60]
	base::OnceCallback<void __cdecl(void)>::Run [0x00007FF949293EF1+97]
	base::debug::TaskAnnotator::RunTask [0x00007FF949311CE3+915]
	base::internal::IncomingTaskQueue::RunTask [0x00007FF9493C75D4+212]
	base::MessageLoop::RunTask [0x00007FF9493D2C82+946]
	base::MessageLoop::DeferOrRunPendingTask [0x00007FF9493D3773+83]
	base::MessageLoop::DoWork [0x00007FF9493D3AB4+532]
	base::MessagePumpForUI::DoRunLoop [0x00007FF9493E25FD+77]
	base::MessagePumpWin::Run [0x00007FF9493E17D7+199]
	base::MessageLoop::Run [0x00007FF9493D239C+524]
	base::RunLoop::Run [0x00007FF9494DF0EA+506]
	content::BrowserMainLoop::MainMessageLoopRun [0x00007FF9384F9A83+403]
	content::BrowserMainLoop::RunMainMessageLoopParts [0x00007FF9384F96B5+517]
[5016:9016:0510/144222.569:37433484:WARNING:discardable_shared_memory_manager.cc(431)] Some MojoDiscardableSharedMemoryManagerImpls are still alive. They will be leaked.
[  FAILED  ] FrameIdTest.RunAsyncTest, where TypeParam =  and GetParam() =  (765 ms)

adding more people who have touched headless recently.

assigned, -sheriff

This may be a dupe of issue 840369.

Looking at the flakiness dashboard, it looks like the bot has recovered 

https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=headless_browsertests&builder=chromium.win%3AWin10%20Tests%20x64%20(dbg)