This might be occurring on other platforms as well, but I only verified on Windows.

Examples:


https://build.chromium.org/p/tryserver.chromium.angle/builders/win_angle_rel_ng/builds/7541

https://chromium-swarm.appspot.com/task?id=39908a6ee4dd5810&refresh=10&show_raw=1

https://build.chromium.org/p/tryserver.chromium.angle/builders/win_angle_rel_ng/builds/7538

https://chromium-swarm.appspot.com/task?id=399063b9cf126110&refresh=10&show_raw=1

https://build.chromium.org/p/tryserver.chromium.angle/builders/win_angle_rel_ng/builds/7536

https://chromium-swarm.appspot.com/task?id=39904a4522527810&refresh=10&show_raw=1

All fail with an error message:

[3688:2016:1101/053520.348:FATAL:activity_tracker.cc(1415)] Check failed: false. Process #2568 was previously recorded as "launched" with no corresponding exit.

Backtrace:
	base::debug::StackTrace::StackTrace [0x6B1E26A0+32]
	base::debug::StackTrace::StackTrace [0x6B1BCB1D+13]
	logging::LogMessage::~LogMessage [0x6B15449E+78]
	base::debug::GlobalActivityTracker::RecordProcessLaunch [0x6B1E65C4+884]
	base::LaunchProcess [0x6B1B462C+1516]
	base::LaunchProcess [0x6B1B3FED+45]
	service_manager::SandboxWin::StartSandboxedProcess [0x6BD95959+267]
	content::StartSandboxedProcess [0x6A7AE1FD+332]
	content::internal::ChildProcessLauncherHelper::LaunchProcessOnLauncherThread [0x6AAA8D4F+411]
	content::internal::ChildProcessLauncherHelper::LaunchOnLauncherThread [0x6AAA806E+258]
	base::debug::TaskAnnotator::RunTask [0x6B216CE5+229]
	base::internal::TaskTracker::RunOrSkipTask [0x6B211EF8+664]
	base::internal::TaskTracker::RunNextTask [0x6B21150B+299]
	base::internal::SchedulerWorker::Thread::ThreadMain [0x6B220733+611]
	base::PlatformThread::GetCurrentThreadPriority [0x6B170A03+467]
	BaseThreadInitThunk [0x768B336A+18]
	RtlInitializeExceptionChain [0x77799902+99]
	RtlInitializeExceptionChain [0x777998D5+54]

Unsure what this is related to, possibly a sandbox problem? Ken can you help triage? This is affecting the stability of the ANGLE CQ.