ToT chrome r458750 on Pixel 1 with --mash in /etc/chrome_dev.conf

* Log in
* Hold down power to shut down

Chrome returns to the login screen instead of shutting down.

[5269:5269:0322/132451.146367:170711087:VERBOSE1:lock_state_controller.cc(363)] StartCancellablePreLockAnimation
[5269:5269:0322/132451.146851:170711568:ERROR:shell_delegate_mus.cc(72)] Not implemented reached in virtual bool ash::ShellDelegateMus::IsRunningInForcedAppMode() const
[5269:5269:0322/132451.146911:170711627:ERROR:accelerator_controller_delegate_mus.cc(60)] Not implemented reached in virtual bool ash::mus::AcceleratorControllerDelegateMus::HandlesAction(ash::AcceleratorAction)
[5269:5269:0322/132451.563438:171128169:VERBOSE1:lock_state_controller.cc(462)] PreLockAnimationFinished
[5268:5268:0322/132451.566400:FATAL:shell.cc(269)] Check failed: HasInstance(). 
#0 0x7fbef2f4401d base::debug::StackTrace::StackTrace()
#1 0x7fbef2f5d3fe logging::LogMessage::~LogMessage()
#2 0x7fbef4ece023 ash::Shell::GetPrimaryRootWindow()
#3 0x7fbef4eeb389 ash::wm::GetActiveWindow()
#4 0x7fbef4eeb250 ash::wm::GetActiveWindowState()
#5 0x7fbef265f59d chromeos::ScreenLocker::Show()
#6 0x7fbef265f90e chromeos::ScreenLocker::HandleLockScreenRequest()
#7 0x7fbef25aa248 chromeos::ScreenLockServiceProvider::LockScreen()
#8 0x7fbef25a9253 _ZN4base8internal7InvokerINS0_9BindStateIMN8chromeos16KioskInfoServiceEFvPN4dbus10MethodCallENS_8CallbackIFvSt10unique_ptrINS5_8ResponseESt14default_deleteISA_EEELNS0_8CopyModeE1ELNS0_10RepeatModeE1EEEEJNS_7WeakPtrIS4_EEEEEFvS7_SH_EE3RunEPNS0_13BindStateBaseEOS7_OSH_
#9 0x7fbef3b5fad4 dbus::ExportedObject::RunMethod()
#10 0x7fbef3b61761 _ZN4base8internal7InvokerINS0_9BindStateIMN4dbus14ExportedObjectEFvNS_8CallbackIFvPNS3_10MethodCallENS5_IFvSt10unique_ptrINS3_8ResponseESt14default_deleteIS9_EEELNS0_8CopyModeE1ELNS0_10RepeatModeE1EEEELSE_1ELSF_1EEES8_IS6_SA_IS6_EENS_9TimeTicksEEJ13scoped_refptrIS4_ESI_NS0_13PassedWrapperISK_EESL_EEEFvvEE3RunEPNS0_13BindStateBaseE
#11 0x7fbef2fe41f3 base::debug::TaskAnnotator::RunTask()
#12 0x7fbef2f654ff base::MessageLoop::RunTask()
#13 0x7fbef2f659ae base::MessageLoop::DeferOrRunPendingTask()
#14 0x7fbef2f67cc0 base::MessageLoop::DoWork()
#15 0x7fbef2f68249 base::MessagePumpLibevent::Run()
#16 0x7fbef2f6526a base::MessageLoop::RunHandler()
#17 0x7fbef2f8ca6d base::RunLoop::Run()
#18 0x7fbef2b60a63 ChromeBrowserMainParts::MainMessageLoopRun()
#19 0x7fbef14c43b0 content::BrowserMainLoop::RunMainMessageLoopParts()
#20 0x7fbef14c8a45 content::BrowserMainRunnerImpl::Run()
#21 0x7fbef14c0779 content::BrowserMain()
#22 0x7fbef2aef766 content::ContentMainRunnerImpl::Run()
#23 0x7fbef410efda service_manager::Main()
#24 0x7fbef2aee1e4 content::ContentMain()
#25 0x7fbef0ef9c1b ChromeMain
#26 0x7fbeee9c2796 __libc_start_main
#27 0x7fbef0ef9a39 _start