Version: ToT debug build
OS: linux

What steps will reproduce the problem?
(1) Not sure, but here is what happened:
(2) I set up a local server to test out: https://bugs.chromium.org/p/chromium/issues/detail?id=622313
(3) After a few runs, it crashed with this DCHECK, and now it happens every time I re-start chrome.

Full backtrace:
[7342:7371:0912/132946:FATAL:url_request.cc(121)] Check failed: !connect_timing->connect_end.is_null(). 
#0 0x7fdd92d9229e base::debug::StackTrace::StackTrace()
#1 0x7fdd92dfb1ef logging::LogMessage::~LogMessage()
#2 0x7fdd9180bd52 net::(anonymous namespace)::ConvertRealLoadTimesToBlockingTimes()
#3 0x7fdd9180b863 net::URLRequest::OnHeadersComplete()
#4 0x7fdd9183bb76 net::URLRequestJob::NotifyHeadersComplete()
#5 0x7fdd91830077 net::URLRequestHttpJob::NotifyHeadersComplete()
#6 0x7fdd91831a68 net::URLRequestHttpJob::SaveCookiesAndNotifyHeadersComplete()
#7 0x7fdd9182dcfd net::URLRequestHttpJob::OnStartCompleted()
#8 0x7fdd90fed778 _ZN4base8internal13FunctorTraitsIMN3net18ClientSocketHandleEFviEvE6InvokeIPS3_JiEEEvS5_OT_DpOT0_
#9 0x7fdd91836f76 _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIRKMN3net17URLRequestHttpJobEFviEJPS5_iEEEvOT_DpOT0_
#10 0x7fdd91836f07 _ZN4base8internal7InvokerINS0_9BindStateIMN3net17URLRequestHttpJobEFviEJNS0_17UnretainedWrapperIS4_EEEEEFviEE7RunImplIRKS6_RKSt5tupleIJS8_EEJLm0EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEEOi
#11 0x7fdd91836cfc _ZN4base8internal7InvokerINS0_9BindStateIMN3net17URLRequestHttpJobEFviEJNS0_17UnretainedWrapperIS4_EEEEEFviEE3RunEPNS0_13BindStateBaseEOi
#12 0x7fdd90fed051 base::Callback<>::Run()
#13 0x7fdd91360771 net::HttpCache::Transaction::DoLoop()
#14 0x7fdd9135e7eb net::HttpCache::Transaction::OnIOComplete()
#15 0x7fdd912527ea _ZN4base8internal13FunctorTraitsIMN10disk_cache11SimpleIndexEFviEvE6InvokeIRKNS_7WeakPtrIS3_EEJiEEEvS5_OT_DpOT0_
#16 0x7fdd91372fcf _ZN4base8internal12InvokeHelperILb1EvE8MakeItSoIRKMN3net9HttpCache11TransactionEFviERKNS_7WeakPtrIS6_EEJiEEEvOT_OT0_DpOT1_
#17 0x7fdd91372f47 _ZN4base8internal7InvokerINS0_9BindStateIMN3net9HttpCache11TransactionEFviEJNS_7WeakPtrIS5_EEEEEFviEE7RunImplIRKS7_RKSt5tupleIJS9_EEJLm0EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEEOi
#18 0x7fdd91372d3c _ZN4base8internal7InvokerINS0_9BindStateIMN3net9HttpCache11TransactionEFviEJNS_7WeakPtrIS5_EEEEEFviEE3RunEPNS0_13BindStateBaseEOi
#19 0x7fdd90fed051 base::Callback<>::Run()
#20 0x7fdd9138a3a3 net::HttpNetworkTransaction::DoCallback()
#21 0x7fdd91385ad8 net::HttpNetworkTransaction::OnIOComplete()
#22 0x7fdd90fed778 _ZN4base8internal13FunctorTraitsIMN3net18ClientSocketHandleEFviEvE6InvokeIPS3_JiEEEvS5_OT_DpOT0_
#23 0x7fdd91392796 _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIRKMN3net22HttpNetworkTransactionEFviEJPS5_iEEEvOT_DpOT0_
#24 0x7fdd91392727 _ZN4base8internal7InvokerINS0_9BindStateIMN3net22HttpNetworkTransactionEFviEJNS0_17UnretainedWrapperIS4_EEEEEFviEE7RunImplIRKS6_RKSt5tupleIJS8_EEJLm0EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEEOi
#25 0x7fdd9139251c _ZN4base8internal7InvokerINS0_9BindStateIMN3net22HttpNetworkTransactionEFviEJNS0_17UnretainedWrapperIS4_EEEEEFviEE3RunEPNS0_13BindStateBaseEOi
#26 0x7fdd90fed051 base::Callback<>::Run()
#27 0x7fdd9150dd69 net::QuicHttpStream::DoCallback()
#28 0x7fdd91510aad net::QuicHttpStream::OnHeadersAvailable()
#29 0x7fdd9152d414 net::QuicChromiumClientStream::NotifyDelegateOfHeadersComplete()
#30 0x7fdd91530653 _ZN4base8internal13FunctorTraitsIMN3net24QuicChromiumClientStreamEFvNS2_15SpdyHeaderBlockEmEvE6InvokeIRKNS_7WeakPtrIS3_EEJS4_RKmEEEvS6_OT_DpOT0_
#31 0x7fdd91530484 _ZN4base8internal12InvokeHelperILb1EvE8MakeItSoIRKMN3net24QuicChromiumClientStreamEFvNS4_15SpdyHeaderBlockEmERKNS_7WeakPtrIS5_EEJS6_RKmEEEvOT_OT0_DpOT1_
#32 0x7fdd915303b2 _ZN4base8internal7InvokerINS0_9BindStateIMN3net24QuicChromiumClientStreamEFvNS3_15SpdyHeaderBlockEmEJNS_7WeakPtrIS4_EENS0_13PassedWrapperIS5_EEmEEEFvvEE7RunImplIRKS7_RKSt5tupleIJS9_SB_mEEJLm0ELm1ELm2EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEE
#33 0x7fdd915300fc _ZN4base8internal7InvokerINS0_9BindStateIMN3net24QuicChromiumClientStreamEFvNS3_15SpdyHeaderBlockEmEJNS_7WeakPtrIS4_EENS0_13PassedWrapperIS5_EEmEEEFvvEE3RunEPNS0_13BindStateBaseE
#34 0x7fdd92d62aed base::Callback<>::Run()
#35 0x7fdd92d97b9b base::debug::TaskAnnotator::RunTask()
#36 0x7fdd92e193dc base::MessageLoop::RunTask()
#37 0x7fdd92e19674 base::MessageLoop::DeferOrRunPendingTask()
#38 0x7fdd92e1993e base::MessageLoop::DoWork()
#39 0x7fdd92e33ebe base::MessagePumpLibevent::Run()
#40 0x7fdd92e18dbf base::MessageLoop::RunHandler()
#41 0x7fdd92ebdf54 base::RunLoop::Run()
#42 0x7fdd92f62778 base::Thread::Run()
#43 0x7fdd8d018946 content::BrowserThreadImpl::IOThreadRun()
#44 0x7fdd8d018c4b content::BrowserThreadImpl::Run()
#45 0x7fdd92f62f1e base::Thread::ThreadMain()
#46 0x7fdd92f4a47a base::(anonymous namespace)::ThreadFunc()
#47 0x7fdd7ef81184 start_thread
#48 0x7fdd7d32837d clone