From this build:

https://luci-milo.appspot.com/buildbot/chromium.gpu.fyi/Win10%20Release%20%28NVIDIA%29/2840

The crash is here:

[4192:5072:0810/201140.409:FATAL:CSSParserImpl.cpp(963)] Check failed: range.Peek().GetType() == kIdentToken (13 vs. 0)
Backtrace:
	base::debug::StackTrace::StackTrace [0x6C448A17+55]
	base::debug::StackTrace::StackTrace [0x6C44302A+10]
	blink::CSSParserImpl::ConsumeDeclaration [0x6DEAEE4B+123]
	blink::CSSParserImpl::ConsumeDeclarationList [0x6DEAF285+522]
	blink::CSSParserImpl::ParseInlineStyleDeclaration [0x6DEB0EA9+203]
	blink::Element::SetInlineStyleFromString [0x6DF13393+242]
	blink::Element::StyleAttributeChanged [0x6DF1402A+392]
	blink::Element::AttributeChanged [0x6DF0C5D8+419]
	blink::HTMLElement::AttributeChanged [0x6D1421D6+16]
	blink::Element::AttributeChangedFromParserOrByCloning [0x6DF0C6E0+71]
	blink::Element::ParserSetAttributes [0x6DF113AA+344]
	blink::AtomicHTMLToken::SelfClosing [0x6E08F812+138]
	blink::HTMLConstructionSite::CreateElement [0x6E08D507+515]
	blink::HTMLConstructionSite::InsertHTMLElement [0x6E08EE1B+22]
	blink::HTMLTreeBuilder::ProcessStartTagForInBody [0x6E099EA4+3807]
	blink::HTMLTreeBuilder::ProcessStartTag [0x6E098783+3062]
	blink::HTMLTreeBuilder::ProcessToken [0x6E09A8B9+127]
	blink::HTMLTreeBuilder::ConstructTree [0x6E09375A+36]
	blink::HTMLDocumentParser::ConstructTreeFromCompactHTMLToken [0x6E066E0A+35]
	blink::HTMLDocumentParser::ProcessTokenizedChunkFromBackgroundParser [0x6E06927C+1245]
	blink::HTMLDocumentParser::PumpPendingSpeculations [0x6E069821+677]
	blink::HTMLDocumentParser::ResumeParsingAfterYield [0x6E069F90+181]
	??$MakeItSo@ABQ8HTMLParserScheduler@blink@@AEXXZABV?$WeakPersistent@VHTMLParserScheduler@blink@@@2@$$V@?$InvokeHelper@$00X@internal@base@@SAXABQ8HTMLParserScheduler@blink@@AEXXZABV?$WeakPersistent@VHTMLParserScheduler@blink@@@4@@Z [0x6DF49320+29]
	base::internal::Invoker<base::internal::BindState<void (__thiscall blink::HTMLParserScheduler::*)(void),blink::WeakPersistent<blink::HTMLParserScheduler> >,void __cdecl(void)>::Run [0x6DF4ADF5+19]
	WTF::Function<void __cdecl(void),1>::operator() [0x6D0094F0+90]
	blink::TaskHandle::Runner::Run [0x6D009954+37]
	base::internal::InvokeHelper<1,void>::MakeItSo<void (__thiscall blink::TaskHandle::Runner::*const &)(blink::TaskHandle const &),base::WeakPtr<blink::TaskHandle::Runner> const &,blink::TaskHandle const &> [0x6D00937D+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 [0x6D00992A+23]
	base::debug::TaskAnnotator::RunTask [0x6C445A6E+398]
	blink::scheduler::TaskQueueManager::ProcessTaskFromWorkQueue [0x6C2E54B4+966]
	blink::scheduler::TaskQueueManager::DoWork [0x6C2E43F0+610]
	base::internal::FunctorTraits<void (__thiscall media::AudioRendererImpl::*)(bool),void>::Invoke<base::WeakPtr<media::AudioRendererImpl> const &,bool> [0x6BAB1E38+26]
	base::internal::InvokeHelper<1,void>::MakeItSo<void (__thiscall media::AudioRendererImpl::*const &)(bool),base::WeakPtr<media::AudioRendererImpl> const &,bool> [0x6BAB1E89+34]
	base::internal::Invoker<base::internal::BindState<void (__thiscall gpu::GpuWatchdogThread::*)(bool),base::WeakPtr<gpu::GpuWatchdogThread>,bool>,void __cdecl(void)>::Run [0x6C2E5A12+23]
	base::debug::TaskAnnotator::RunTask [0x6C445A6E+398]
	base::MessageLoop::RunTask [0x6C410E31+1233]
	base::MessageLoop::DoWork [0x6C41029F+655]
	base::MessagePumpDefault::Run [0x6C463D3B+219]
	base::MessageLoop::Run [0x6C41094B+107]
	base::RunLoop::Run [0x6C42ED6C+156]
	content::RendererMain [0x6D4A7D35+477]
	content::RunNamedProcessTypeMain [0x6C3CB99B+176]
	content::ContentMainRunnerImpl::Run [0x6C3CB8BA+286]
	service_manager::Main [0x6C3D1F23+558]
	content::ContentMain [0x6C3CAF7A+39]
	ChromeMain [0x6B96D193+214]
	MainDllLoader::Launch [0x000F6324+445]
	wWinMain [0x000F414B+557]
	

The cause is almost surely this CL:

https://chromium-review.googlesource.com/597607

Reverting.

Reverted in https://chromium-review.googlesource.com/612371 .