I managed to get a crash call stack:
#0  0x00007fffe1f57956 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1  0x00007fffe1f579a0 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#2  0x00007fffed9d3c85 in __gnu_debug::_Safe_iterator_base::_Safe_iterator_base(__gnu_debug::_Safe_sequence_base const*, bool) ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#3  0x00007fffedcb7e30 in __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<chromeos::Printer const*, std::__cxx1998::vector<chromeos::Printer, std::allocator<chromeos::Printer> > >, std::__debug::vector<chromeos::Printer, std::allocator<chromeos::Printer> > >::_Safe_iterator(__gnu_cxx::__normal_iterator<chromeos::Printer const*, std::__cxx1998::vector<chromeos::Printer, std::allocator<chromeos::Printer> > > const&, std::__debug::vector<chromeos::Printer, std::allocator<chromeos::Printer> > const*) ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#4  0x00007fffedcb473f in std::__debug::vector<chromeos::Printer, std::allocator<chromeos::Printer> >::cbegin() const ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#5  0x00007fffedcb2be9 in chromeos::FakePrinterDiscoverer::EmitPrinters(unsigned long, unsigned long) ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#6  0x00007fffedcb5757 in void base::internal::FunctorTraits<void (chromeos::FakePrinterDiscoverer::*)(unsigned long, unsigned long), void>::Invoke<base::WeakPtr<chromeos::FakePrinterDiscoverer> const&, int const&, int const&>(void (chromeos::FakePrinterDiscoverer::*)(unsigned long, unsigned long), base::WeakPtr<chromeos::FakePrinterDiscoverer> const&, int const&, int const&) ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#7  0x00007fffedcb5634 in void base::internal::InvokeHelper<true, void>::MakeItSo<void (chromeos::FakePrinterDiscoverer::* const&)(unsigned long, unsigned long), base::WeakPtr<chromeos::FakePrinterDiscoverer> const&, int const&, int const&>(void (chromeos::FakePrinterDiscoverer::* const&)(unsigned long, unsigned long), base::WeakPtr<chromeos::FakePrinterDiscoverer> const&, int const&, int const&) () from /work/chromiumos/src/out/Default/./libchromeos.so
#8  0x00007fffedcb5594 in void base::internal::Invoker<base::internal::BindState<void (chromeos::FakePrinterDiscoverer::*)(unsigned long, unsigned long), base::WeakPtr<chromeos::FakePrinterDiscoverer>, int, int>, void ()>::RunImpl<void (chromeos::FakePrinterDiscoverer::* const&)(unsigned long, unsigned long), std::tuple<base::WeakPtr<chromeos::FakePrinterDiscoverer>, int, int> const&, 0ul, 1ul, 2ul>(void (chromeos::FakePrinterDiscoverer::* const&)(unsigned long, unsigned long), std::tuple<base::WeakPtr<chromeos::FakePrinterDiscoverer>, int, int> const&, base::IndexSequence<0ul, 1ul, 2ul>) ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#9  0x00007fffedcb546c in base::internal::Invoker<base::internal::BindState<void (chromeos::FakePrinterDiscoverer::*)(unsigned long, unsigned long), base::WeakPtr<chromeos::FakePrinterDiscoverer>, int, int>, void ()>::Run(base::internal::BindStateBase*) ()
   from /work/chromiumos/src/out/Default/./libchromeos.so
#10 0x00007ffff77b8091 in base::internal::RunMixin<base::Callback<void (), (base::internal::CopyMode)0, (base::internal::RepeatMode)0> >::Run() && () from /work/chromiumos/src/out/Default/./libbase.so
#11 0x00007ffff77b7ac9 in base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask*) ()
   from /work/chromiumos/src/out/Default/./libbase.so
#12 0x00007ffff78419af in base::MessageLoop::RunTask(base::PendingTask*) () from /work/chromiumos/src/out/Default/./libbase.so
#13 0x00007ffff7841c14 in base::MessageLoop::DeferOrRunPendingTask(base::PendingTask) ()
   from /work/chromiumos/src/out/Default/./libbase.so
#14 0x00007ffff784218c in base::MessageLoop::DoDelayedWork(base::TimeTicks*) ()
   from /work/chromiumos/src/out/Default/./libbase.so
---Type <return> to continue, or q <return> to quit--- 
#15 0x00007ffff78575c8 in base::MessagePumpGlib::Run(base::MessagePump::Delegate*) ()
   from /work/chromiumos/src/out/Default/./libbase.so
#16 0x00007ffff7841575 in base::MessageLoop::RunHandler() () from /work/chromiumos/src/out/Default/./libbase.so
#17 0x00007ffff78ddde4 in base::RunLoop::Run() () from /work/chromiumos/src/out/Default/./libbase.so
#18 0x000055555779a4b7 in ChromeBrowserMainParts::MainMessageLoopRun(int*) ()
#19 0x00007ffff1353916 in content::BrowserMainLoop::RunMainMessageLoopParts() ()
   from /work/chromiumos/src/out/Default/./libcontent.so
#20 0x00007ffff135e985 in content::BrowserMainRunnerImpl::Run() () from /work/chromiumos/src/out/Default/./libcontent.so
#21 0x00007ffff134d8d8 in content::BrowserMain(content::MainFunctionParams const&) ()
   from /work/chromiumos/src/out/Default/./libcontent.so
#22 0x00007ffff295ac26 in content::RunNamedProcessTypeMain(std::string const&, content::MainFunctionParams const&, content::ContentMainDelegate*) () from /work/chromiumos/src/out/Default/./libcontent.so
#23 0x00007ffff295ca85 in content::ContentMainRunnerImpl::Run() () from /work/chromiumos/src/out/Default/./libcontent.so
#24 0x00007ffff2959ff2 in content::ContentMain(content::ContentMainParams const&) ()
   from /work/chromiumos/src/out/Default/./libcontent.so
#25 0x0000555555ce9691 in ChromeMain ()
#26 0x0000555555ce95b2 in main ()

CL https://codereview.chromium.org/2466993005/ is under review.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e199cde96ef5e0f486624339b41cc72f3e3793ec

commit e199cde96ef5e0f486624339b41cc72f3e3793ec
Author: xdai <xdai@chromium.org>
Date: Thu Nov 03 18:06:51 2016

[CUPS] Fix the occasional crash when switching between different dialogs.

We had some feedback from the testing team: Chrome crashes something -
typically when switching between the printer discovery dialog and the
manually add printer dialog.

BUG= 662077 , 626752

Review-Url: https://codereview.chromium.org/2466993005
Cr-Commit-Position: refs/heads/master@{#429648}

[modify] https://crrev.com/e199cde96ef5e0f486624339b41cc72f3e3793ec/chromeos/printing/fake_printer_discoverer.cc
[modify] https://crrev.com/e199cde96ef5e0f486624339b41cc72f3e3793ec/chromeos/printing/fake_printer_discoverer.h
[modify] https://crrev.com/e199cde96ef5e0f486624339b41cc72f3e3793ec/chromeos/printing/printer_discoverer.h