Encountered this when trying to get the active frame index in SurfaceAggregator and HitTestManager in --mash.

stacktrace:

[70267:70296:1031/172235.852446:FATAL:optional.h(177)] Check failed: !storage_.is_null_. 
#0 0x7f08b5473d9c base::debug::StackTrace::StackTrace()
#1 0x7f08b549a36c logging::LogMessage::~LogMessage()
#2 0x7f08af9a61aa base::Optional<>::operator->()
#3 0x7f08af9d5324 viz::SurfaceAggregator::PrewalkTree()
#4 0x7f08af9d66e2 viz::SurfaceAggregator::PrewalkTree()
#5 0x7f08af9d66e2 viz::SurfaceAggregator::PrewalkTree()
#6 0x7f08af9d764d viz::SurfaceAggregator::Aggregate()
#7 0x7f08af9a4011 viz::Display::DrawAndSwap()
#8 0x7f08af9a7e5a viz::DisplayScheduler::DrawAndSwap()
#9 0x7f08af9a751f viz::DisplayScheduler::AttemptDrawAndSwap()
#10 0x7f08af9a6e16 viz::DisplayScheduler::OnBeginFrameDeadline()
#11 0x7f08af9a9ac7 _ZN4base8internal7InvokerINS0_9BindStateIMN3viz16DisplaySchedulerEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE3RunEPNS0_13BindStateBaseE
#12 0x7f08af9a9d3f _ZN4base8internal22CancelableCallbackImplINS_17RepeatingCallbackIFvvEEEE16ForwardRepeatingIJEEEvDpT_
#13 0x7f08af9a9ac7 _ZN4base8internal7InvokerINS0_9BindStateIMN3viz16DisplaySchedulerEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE3RunEPNS0_13BindStateBaseE
#14 0x7f08b5474675 base::debug::TaskAnnotator::RunTask()
#15 0x7f08b54a5709 base::internal::IncomingTaskQueue::RunTask()
#16 0x7f08b54a92c8 base::MessageLoop::RunTask()
#17 0x7f08b54a962a base::MessageLoop::DeferOrRunPendingTask()
#18 0x7f08b54a9b87 base::MessageLoop::DoDelayedWork()
#19 0x7f08b54aadcd base::MessagePumpDefault::Run()
#20 0x7f08b54a8c19 base::MessageLoop::Run()
#21 0x7f08b54dd1e8 base::RunLoop::Run()
#22 0x7f08b551cb47 base::Thread::Run()
#23 0x7f08b551d0fc base::Thread::ThreadMain()
#24 0x7f08b5513e8f base::(anonymous namespace)::ThreadFunc()
#25 0x7f08b55f0184 start_thread
#26 0x7f08a9353ffd clone

Received signal 6
#0 0x7f08b5473d9c base::debug::StackTrace::StackTrace()
#1 0x7f08b5473881 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7f08b55f8330 <unknown>
#3 0x7f08a928cc37 gsignal
#4 0x7f08a9290028 abort
#5 0x7f08b5471795 base::debug::BreakDebugger()
#6 0x7f08b549a720 logging::LogMessage::~LogMessage()
#7 0x7f08af9a61aa base::Optional<>::operator->()
#8 0x7f08af9d5324 viz::SurfaceAggregator::PrewalkTree()
#9 0x7f08af9d66e2 viz::SurfaceAggregator::PrewalkTree()
#10 0x7f08af9d66e2 viz::SurfaceAggregator::PrewalkTree()
#11 0x7f08af9d764d viz::SurfaceAggregator::Aggregate()
#12 0x7f08af9a4011 viz::Display::DrawAndSwap()
#13 0x7f08af9a7e5a viz::DisplayScheduler::DrawAndSwap()
#14 0x7f08af9a751f viz::DisplayScheduler::AttemptDrawAndSwap()
#15 0x7f08af9a6e16 viz::DisplayScheduler::OnBeginFrameDeadline()
#16 0x7f08af9a9ac7 _ZN4base8internal7InvokerINS0_9BindStateIMN3viz16DisplaySchedulerEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE3RunEPNS0_13BindStateBaseE
#17 0x7f08af9a9d3f _ZN4base8internal22CancelableCallbackImplINS_17RepeatingCallbackIFvvEEEE16ForwardRepeatingIJEEEvDpT_
#18 0x7f08af9a9ac7 _ZN4base8internal7InvokerINS0_9BindStateIMN3viz16DisplaySchedulerEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE3RunEPNS0_13BindStateBaseE
#19 0x7f08b5474675 base::debug::TaskAnnotator::RunTask()
#20 0x7f08b54a5709 base::internal::IncomingTaskQueue::RunTask()
#21 0x7f08b54a92c8 base::MessageLoop::RunTask()
#22 0x7f08b54a962a base::MessageLoop::DeferOrRunPendingTask()
#23 0x7f08b54a9b87 base::MessageLoop::DoDelayedWork()
#24 0x7f08b54aadcd base::MessagePumpDefault::Run()
#25 0x7f08b54a8c19 base::MessageLoop::Run()
#26 0x7f08b54dd1e8 base::RunLoop::Run()
#27 0x7f08b551cb47 base::Thread::Run()
#28 0x7f08b551d0fc base::Thread::ThreadMain()
#29 0x7f08b5513e8f base::(anonymous namespace)::ThreadFunc()
#30 0x7f08b55f0184 start_thread
#31 0x7f08a9353ffd clone
  r8: ffffbf8c6255c430  r9: ffffbf8c6255c420 r10: 0000000000000008 r11: 0000000000000206
 r12: 00007f089b1095a8 r13: 00007f089b109598 r14: 00007f089b1095a0 r15: 00007f089b1090f0
  di: 000000000001127b  si: 0000000000011298  bp: 00007f089b1090e0  bx: 00007f089b1090f0
  dx: 0000000000000006  ax: 0000000000000000  cx: 00007f08a928cc37  sp: 00007f089b108fa8
  ip: 00007f08a928cc37 efl: 0000000000000206 cgf: 0000000000000033 erf: 0000000000000000
 trp: 0000000000000000 msk: 0000000000000000 cr2: 0000000000000000
[end of stack trace]