In this build:
https://ci.chromium.org/buildbot/chromium.gpu.fyi/Win7%20Release%20%28NVIDIA%29/31868

The test GpuCrash_GPUProcessCrashesExactlyOncePerVisitToAboutGpuCrash failed because (I think) a NOTREACHED was hit inside base::debug::GlobalActivityTracker::RecordProcessLaunch :

  Symbolized minidump:
  Last event: 484.938: Break instruction exception - code 80000003 (first/second chance not available)
    debugger time: Fri Oct 27 11:53:12.465 2017 (UTC - 7:00)
  ChildEBP RetAddr  Args to Child              
  06acee3c 67c8d747 69a68e3d 00000587 0717020c chrome!base::debug::BreakDebugger+0xc
  06acee64 67bbdc0e 010389b0 06aceeb0 06aceeb4 chrome!?Run@?$Invoker@U?$BindState@P6AXPBDHV?$BasicStringPiece@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@base@@1@Z$$V@internal@base@@$$A6AXPBDHV?$BasicStringPiece@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@3@1@Z@internal@base@@SAXPAVBindStateBase@23@$$QAPBD$$QAH$$QAV?$BasicStringPiece@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@3@3@Z+0x25
  06acf2f8 67c4d414 00000000 0103da58 00000000 chrome!logging::LogMessage::~LogMessage+0x41e
  06acf400 687e9657 0000063c 06acf4c0 00000000 chrome!base::debug::GlobalActivityTracker::RecordProcessLaunch+0x2f4
  06acf6e4 6721dcc5 08475ce8 06acf758 06acf7ac chrome!service_manager::SandboxWin::StartSandboxedProcess+0xbc9
  06acf788 675168cf 0c1cf9b0 08475ce8 06acf7ac chrome!content::StartSandboxedProcess+0x14c
  06acf894 67515b82 06acf8c8 06acf8e0 00000000 chrome!content::internal::ChildProcessLauncherHelper::LaunchProcessOnLauncherThread+0x19b
  06acf9a4 67c7e395 08478a38 00310f9f 67bc175d chrome!content::internal::ChildProcessLauncherHelper::LaunchOnLauncherThread+0x102
  06acfac8 67c79159 69a6f557 0821dd48 01010148 chrome!base::debug::TaskAnnotator::RunTask+0xe5
  06acfc04 67c7878b 0821dd48 0108eb08 00000001 chrome!base::internal::TaskTracker::RunOrSkipTask+0x279
  06acfd04 67c87f93 06acfd30 0108eb08 0108eab8 chrome!base::internal::TaskTracker::RunNextTask+0x12b
  06acfdf8 67bd9f23 010a9210 00000440 00000440 chrome!base::internal::SchedulerWorker::Thread::ThreadMain+0x263


bcwhite: I see a TODO in the associated code assigned to you:
https://cs.chromium.org/chromium/src/base/debug/activity_tracker.cc?type=cs&sq=package:chromium&l=1414

Can I please assign you this bug? This test deliberately crashes Chrome's GPU sub-process, which may tease out various race conditions. However it's expected that the browser will handle this reliably.