OS: Windows
Test Suite: viz_browser_tests
           (browser_tests -enable-features=VizDisplayCompositor)
Test Case: SupervisedUserBlockModeTest.Unblock/0 Flaky

Example failing build: https://ci.chromium.org/buildbot/tryserver.chromium.win/win7_chromium_rel_ng/138083

Stack Trace of the failure:

[4816:2184:0404/225710.274:FATAL:interstitial_page_impl.cc(644)] Check failed: false.
Backtrace:
	base::debug::StackTrace::StackTrace [0x03722230+32]
	base::debug::StackTrace::StackTrace [0x036E734D+13]
	logging::LogMessage::~LogMessage [0x0368DE93+83]
	content::InterstitialPageImpl::Proceed [0x02556282+98]
	SupervisedUserService::OnSiteListUpdated [0x056A246F+79]
	SupervisedUserURLFilter::SetContents [0x056A56B0+176]
	base::internal::FunctorTraits<void (__thiscall content::VideoDecoderShim::*)(std::unique_ptr<content::VideoDecoderShim::PendingFrame,std::default_delete<content::VideoDecoderShim::PendingFrame> >),void>::Invoke<base::WeakPtr<content::VideoDecoderShim>,std [0x0572965B+47]
	base::internal::Invoker<base::internal::BindState<void (__thiscall policy::URLBlacklistManager::*)(std::unique_ptr<policy::URLBlacklist,std::default_delete<policy::URLBlacklist> >),base::WeakPtr<policy::URLBlacklistManager> >,void __cdecl(std::unique_ptr< [0x038BFDCD+61]
	base::OnceCallback<void __cdecl(std::unique_ptr<SupervisedUserURLFilter::Contents,std::default_delete<SupervisedUserURLFilter::Contents> >)>::Run [0x056A711C+48]
	base::internal::ReplyAdapter<std::unique_ptr<SupervisedUserURLFilter::Contents,std::default_delete<SupervisedUserURLFilter::Contents> >,std::unique_ptr<SupervisedUserURLFilter::Contents,std::default_delete<SupervisedUserURLFilter::Contents> > > [0x056A6F8C+44]
	base::internal::FunctorTraits<void (__cdecl*)(base::OnceCallback<bool __cdecl(void)>,bool *),void>::Invoke<base::OnceCallback<bool __cdecl(void)>,bool *> [0x0281D1DB+43]
	base::internal::Invoker<base::internal::BindState<void (__cdecl*)(base::OnceCallback<void __cdecl(bool,history::URLRow const &,std::vector<history::VisitRow,std::allocator<history::VisitRow> > const &)>,history::QueryURLResult const *),base::OnceCallback< [0x0281D199+41]
	base::internal::PostTaskAndReplyImpl::PostTaskAndReply [0x037338A4+1348]
	base::debug::TaskAnnotator::RunTask [0x0371E8FD+237]
	base::internal::IncomingTaskQueue::RunTask [0x03741D49+105]
	base::MessageLoop::RunTask [0x036C2E27+519]
...

I've added the SiteIsolation tag to help triage from the InterstitialPageImpl aspect. However that method has been stable for years.

bauerb@ as an owner of chrome/browser/supervised_user could you help triage this?

Marking this as P1 as the flakes have been affecting a significant number of jobs on the CQ