Chrome crashes repeatedly after creating new user.

(Another scenario: chrome crashes in multiprofile session.)

Build debug version of chrome, deploy to device. Try to create new user. Chrome will crash with crbug.com/614247 first, and then repeatedly with this:

[17137:17137:0523/204837:FATAL:child_process_task_provider.cc(147)] Check failed: false. 
#0 0x7f2c255c8d2b base::debug::StackTrace::StackTrace()
#1 0x7f2c25607dcf logging::LogMessage::~LogMessage()
#2 0x7f2c25135d76 task_management::ChildProcessTaskProvider::DeleteTask()
#3 0x7f2c251353d1 task_management::ChildProcessTaskProvider::BrowserChildProcessHostDisconnected()
#4 0x7f2c2ae7ceae content::(anonymous namespace)::NotifyProcessHostDisconnected()
#5 0x7f2c2485eb03 _ZN4base8internal15RunnableAdapterIPFvRKSsEE3RunIJS3_EEEvDpOT_
#6 0x7f2c2485d52a _ZN4base8internal12InvokeHelperILb0EvNS0_15RunnableAdapterIPFvRKSsEEEE8MakeItSoIJS4_EEEvS7_DpOT_
#7 0x7f2c2ae837f2 _ZN4base8internal7InvokerINS_13IndexSequenceIJLm0EEEENS0_9BindStateINS0_15RunnableAdapterIPFvRKN7content16ChildProcessDataEEEESA_JRS7_EEENS0_12InvokeHelperILb0EvSC_EEFvvEE3RunEPNS0_13BindStateBaseE
#8 0x7f2c248bb9a6 base::Callback<>::Run()
#9 0x7f2c2572f1d9 base::debug::TaskAnnotator::RunTask()
#10 0x7f2c2561d24f base::MessageLoop::RunTask()
#11 0x7f2c2561d372 base::MessageLoop::DeferOrRunPendingTask()
#12 0x7f2c2561d961 base::MessageLoop::DoWork()
#13 0x7f2c255a877e base::MessagePumpLibevent::Run()
#14 0x7f2c2561ce63 base::MessageLoop::RunHandler()
#15 0x7f2c2568a04f base::RunLoop::Run()
#16 0x7f2c2f03361b ChromeBrowserMainParts::MainMessageLoopRun()
#17 0x7f2c2b527aed content::BrowserMainLoop::RunMainMessageLoopParts()
#18 0x7f2c2ae8f395 content::BrowserMainRunnerImpl::Run()
#19 0x7f2c2ae8e796 content::BrowserMain()
#20 0x7f2c25545bc8 content::RunNamedProcessTypeMain()
#21 0x7f2c25546dca content::ContentMainRunnerImpl::Run()
#22 0x7f2c25544ee0 content::ContentMain()
#23 0x7f2c247b152a ChromeMain
#24 0x7f2c247b14c0 main
#25 0x7f2c2201efb6 __libc_start_main
#26 0x7f2c247b134b <unknown>


Another scenario: add second user to multiprofile session. In about a minute debug chrome will crash with the stack trace above.

It actually looks like a race, so my scenarios might just change the timings.