And, I need to add that there actually is a crash - as seen below:

$ cat out/rel/layout-test-results/external/wpt/fetch/corb/img-mime-types-coverage.tentative.sub-stderr.txt 
[220506:220513:0625/151541.308608:WARNING:file_path_watcher_linux.cc(656)] Watch failed for /etc/resolvconf/run: No such file or directory (2)
Received signal 11 SEGV_MAPERR 000000000008
#0 0x7feb1f1ae0bc base::debug::StackTrace::StackTrace()
#1 0x7feb1f1adb91 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7feb151460c0 <unknown>
#3 0x7feb1b0191b0 network::mojom::URLLoaderClientProxy::OnReceiveResponse()
#4 0x7feb1afde589 network::URLLoader::SendResponseToClient()
#5 0x7feb1afdba66 network::URLLoader::NotifyCompleted()
#6 0x7feb1f3a38f9 mojo::InterfaceEndpointClient::NotifyError()
#7 0x7feb1f3ab0c3 mojo::internal::MultiplexRouter::ProcessNotifyErrorTask()
#8 0x7feb1f3a7d2b mojo::internal::MultiplexRouter::ProcessTasks()
#9 0x7feb1f3a6338 mojo::internal::MultiplexRouter::OnPipeConnectionError()
#10 0x7feb1f39be90 mojo::Connector::HandleError()
#11 0x7feb1f39ce1c mojo::Connector::OnHandleReadyInternal()
#12 0x7feb1f39d7d4 mojo::SimpleWatcher::DiscardReadyState()
#13 0x7feb1f3dd783 mojo::SimpleWatcher::OnHandleReady()
#14 0x7feb1f3ddc11 mojo::SimpleWatcher::Context::Notify()
#15 0x7feb1f3dc623 mojo::SimpleWatcher::Context::CallNotify()
#16 0x7feb0e8f8187 mojo::edk::WatcherDispatcher::InvokeWatchCallback()
#17 0x7feb0e8f7892 mojo::edk::Watch::InvokeCallback()
#18 0x7feb0e8f249a mojo::edk::RequestContext::~RequestContext()
#19 0x7feb0e8e431d mojo::edk::NodeChannel::OnChannelMessage()
#20 0x7feb0e8d0740 mojo::edk::Channel::OnReadComplete()
#21 0x7feb0e8fef69 mojo::edk::(anonymous namespace)::ChannelPosix::OnFileCanReadWithoutBlocking()
#22 0x7feb1f1d08ac base::MessagePumpLibevent::OnLibeventNotification()
#23 0x7feb1f1e887d event_base_loop
#24 0x7feb1f1d0b2e base::MessagePumpLibevent::Run()
#25 0x7feb1f107581 base::MessageLoop::Run()
#26 0x7feb1f13b266 base::RunLoop::Run()
#27 0x7feb1f178aea base::Thread::Run()
#28 0x7feb1f17906f base::Thread::ThreadMain()
#29 0x7feb1f1c327f base::(anonymous namespace)::ThreadFunc()
#30 0x7feb1513c494 start_thread
#31 0x7feb14b78a8f clone
  r8: 0000000000000000  r9: 00007feb1f1f5e10 r10: 0000293355eb2848 r11: 0000000000000246
 r12: 000029335608e000 r13: 000029335609f880 r14: 0000293355e98308 r15: 0000000000000000
  di: 0000000000000000  si: 0000293355e98308  bp: 00007feb03f08590  bx: 0000000000000000
  dx: 0000000000000071  ax: bcc7fedb0710bb00  cx: 0000000000000086  sp: 00007feb03f08500
  ip: 00007feb1b0191b0 efl: 0000000000010206 cgf: 002b000000000033 erf: 0000000000000004
 trp: 000000000000000e msk: 0000000000000000 cr2: 0000000000000008
[end of stack trace]
Calling _exit(1). Core file will not be generated.

Also - the crash here only happen in a broken version of https://chromium-review.googlesource.com/c/chromium/src/+/1108746 (i.e. the crash won't happen at ToT).

jam@, can you PTAL and triage it further / help find the right owner?