Original reproduction files attached. Loading them up in a dcheck-enabled ToT build throws the following stack trace for me. I did have to refresh the page once or twice originally to get it to fire.

[1:1:0920/130943.104892:FATAL:web_document_subresource_filter_impl.cc(175)] Check failed: !main_task_runner_->BelongsToCurrentThread(). 
#0 0x7f7ce54add1c base::debug::StackTrace::StackTrace()
#1 0x7f7ce53d7f1b logging::LogMessage::~LogMessage()
#2 0x5605ffacd204 subresource_filter::WebDocumentSubresourceFilterImpl::BuilderImpl::Build()
#3 0x7f7ce2fe90fe content::WebWorkerFetchContextImpl::TakeSubresourceFilter()
#4 0x7f7cdd0e5d77 blink::WorkerFetchContext::WorkerFetchContext()
#5 0x7f7cdd0e5aa7 blink::WorkerFetchContext::Create()
#6 0x7f7cdd3b6a75 blink::WorkerOrWorkletGlobalScope::EnsureFetcher()
#7 0x7f7cdd27c2aa blink::WorkletModulatorImpl::CreateModuleScriptFetcher()
#8 0x7f7cdd0be9e5 blink::ModuleScriptLoader::FetchInternal()
#9 0x7f7cdd26ca09 blink::ModuleMap::FetchSingleModuleScript()
#10 0x7f7cdd0c0742 blink::ModuleTreeLinker::FetchRoot()
#11 0x7f7cdd0c039c blink::ModuleTreeLinker::Fetch()
#12 0x7f7cdd269db0 blink::ModulatorImplBase::FetchTree()
#13 0x7f7cdd3b72ce blink::WorkerOrWorkletGlobalScope::FetchModuleScript()
#14 0x7f7cdd3c0d94 blink::WorkletGlobalScope::FetchAndInvokeScript()
#15 0x7f7cda651432 blink::PaintWorkletGlobalScopeProxy::FetchAndInvokeScript()
#16 0x7f7cdd3be4e0 blink::Worklet::FetchAndInvokeScript()
#17 0x7f7cdc35fe59 WTF::ThreadCheckingCallbackWrapper<>::Run()
#18 0x7f7ce53b8aed base::debug::TaskAnnotator::RunTask()
#19 0x7f7ce544a630 base::sequence_manager::internal::ThreadControllerImpl::DoWork()
#20 0x7f7ce544c828 _ZN4base8internal7InvokerINS0_9BindStateIMNS_16sequence_manager8internal20ThreadControllerImplEFvNS5_8WorkTypeEEJNS_7WeakPtrIS5_EES6_EEEFvvEE3RunEPNS0_13BindStateBaseE
#21 0x7f7ce53b8aed base::debug::TaskAnnotator::RunTask()
#22 0x7f7ce53e5a3e base::MessageLoop::RunTask()
#23 0x7f7ce53e5f02 base::MessageLoop::DoWork()
#24 0x7f7ce53e9946 base::MessagePumpDefault::Run()
#25 0x7f7ce53e5511 base::MessageLoop::Run()
#26 0x7f7ce5419546 base::RunLoop::Run()
#27 0x7f7ce316efe2 content::RendererMain()
#28 0x7f7ce323f1a7 content::RunZygote()
#29 0x7f7ce32403b7 content::ContentMainRunnerImpl::Run()
#30 0x7f7ce5724b19 service_manager::Main()
#31 0x7f7ce323e761 content::ContentMain()
#32 0x5605fdc9f1b3 ChromeMain
#33 0x7f7cd71a62b1 __libc_start_main
#34 0x5605fdc9f02a _start

 

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Deleted: foopainter.js 324 bytes

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