Running "chrome --enable-ui-devtools=4568 --mash" and connected with devtools
ToT 61.0.3140.0

Received signal 11 SEGV_MAPERR 0000000002c0
#0 0x7fb01c46ab6c base::debug::StackTrace::StackTrace()
#1 0x7fb01c46a6d1 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7fb01c5ab330 <unknown>
#3 0x7fb01844f334 views::Widget::GetRestoredBounds()
#4 0x5576e9fafff2 ui_devtools::WidgetElement::GetBounds()
#5 0x5576e9faa8b9 ui_devtools::UIDevToolsCSSAgent::getMatchedStylesForNode()
#6 0x5576e9faa932 ui_devtools::UIDevToolsCSSAgent::getMatchedStylesForNode()
#7 0x7fb017777383 ui_devtools::protocol::CSS::DispatcherImpl::getMatchedStylesForNode()
#8 0x7fb017776fa0 ui_devtools::protocol::CSS::DispatcherImpl::dispatch()
#9 0x7fb017781347 ui_devtools::protocol::UberDispatcher::dispatch()
#10 0x7fb017785d6d ui_devtools::UiDevToolsClient::Dispatch()
#11 0x7fb01c46b502 base::debug::TaskAnnotator::RunTask()
#12 0x7fb01c490a7b base::MessageLoop::RunTask()
#13 0x7fb01c490e4b base::MessageLoop::DeferOrRunPendingTask()
#14 0x7fb01c4912b1 base::MessageLoop::DoWork()
#15 0x7fb01c492b69 base::MessagePumpLibevent::Run()
#16 0x7fb01c4bb3a3 base::RunLoop::Run()
#17 0x5576ea0d5908 ChromeBrowserMainParts::MainMessageLoopRun()
#18 0x7fb01a06c877 content::BrowserMainLoop::RunMainMessageLoopParts()
#19 0x7fb01a06eec2 content::BrowserMainRunnerImpl::Run()
#20 0x7fb01a06860f content::BrowserMain()
#21 0x7fb01a6d4f97 content::ContentMainRunnerImpl::Run()
#22 0x7fb01c97721b service_manager::Main()
#23 0x7fb01a6d3f54 content::ContentMain()
#24 0x5576e9902c7f ChromeMain
#25 0x7fb011bd5f45 __libc_start_main
#26 0x5576e9902ae4 <unknown>
  r8: 0000000000000199  r9: 00002da4e54b9b58 r10: 00007ffdc94e3868 r11: 00007fb011d3dcf0
 r12: 00000000000002c4 r13: 00007ffdc94e3870 r14: 00007ffdc94e3910 r15: 00007ffdc94e3938
  di: 00000000000002c0  si: 00007ffdc94e3870  bp: 00007ffdc94e3860  bx: 00007ffdc94e3870
  dx: 000000000000012b  ax: 00005576ec76ba40  cx: 00002da4e58e3dd0  sp: 00007ffdc94e3848
  ip: 00007fb01844f334 efl: 0000000000010206 cgf: 0000000000000033 erf: 0000000000000004
 trp: 000000000000000e msk: 0000000000000000 cr2: 00000000000002c0
[end of stack trace]

Similar to  bug 736369 .
Expanding the tree, clicking on the [only] browser window and Chrome OS (simulation) system UI. No clear steps though, will update if I get clear steps.