Able to reproduce the issue on 55.0.2852.0/8780.0.0 dev channel falco.


Stack trace of the crash id b36f1a1500000000:
=============================================

Thread 0 CRASHED [SIGSEGV @ 0x00000110 ] MAGIC SIGNATURE THREAD
0x00007f36893f72b0	(chrome -sync_backend_registrar.cc:370 )	browser_sync::SyncBackendRegistrar::sync_thread
0x00007f36875f0dcf	(chrome -update_screen.cc:291 )	chromeos::UpdateScreen::OnPortalDetectionCompleted
0x00007f368763a249	(chrome -network_portal_detector_impl.cc:276 )	chromeos::NetworkPortalDetectorImpl::AddAndFireObserver
0x00007f36876302df	(chrome -wizard_controller.cc:819 )	chromeos::WizardController::InitiateOOBEUpdate
0x00007f3687631cf7	(chrome -wizard_controller.cc:1018 )	chromeos::WizardController::OnExit
0x00007f36893ed76f	(chrome -callback.h:61 )	login::CallbackWrapper<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >&>
0x00007f36870a9720	(chrome -callback.h:61 )	content::WebUIImpl::ProcessWebUIMessage
0x00007f36870aa96b	(chrome -tuple.h:144 )	content::WebUIImpl::OnMessageReceived
0x00007f36861dc5dd	(chrome -web_contents_impl.cc:654 )	content::WebContentsImpl::OnMessageReceived
0x00007f3686fdcb6f	(chrome -render_view_host_impl.cc:836 )	content::RenderViewHostImpl::OnMessageReceived
0x00007f3686fe8f55	(chrome -render_widget_host_impl.cc:459 )	content::RenderWidgetHostImpl::OnMessageReceived
0x00007f3686fd7d19	(chrome -render_process_host_impl.cc:1964 )	content::RenderProcessHostImpl::OnMessageReceived
0x00007f368845ff56	(chrome -ipc_channel_proxy.cc:314 )	IPC::ChannelProxy::Context::OnDispatchMessage
0x00007f368620756b	(chrome -callback.h:61 )	base::debug::TaskAnnotator::RunTask
0x00007f36861f05fd	(chrome -message_loop.cc:488 )	base::MessageLoop::DoWork
0x00007f36861f0f72	(chrome -message_pump_libevent.cc:217 )	base::MessagePumpLibevent::Run
0x00007f3687bec367	(chrome -run_loop.cc:35 )	base::RunLoop::Run
0x00007f36878edd34	(chrome -chrome_browser_main.cc:2098 )	ChromeBrowserMainParts::MainMessageLoopRun
0x00007f3686e0444a	(chrome -browser_main_loop.cc:954 )	content::BrowserMainLoop::RunMainMessageLoopParts
0x00007f3686e062e4	(chrome -browser_main_runner.cc:155 )	content::BrowserMainRunnerImpl::Run
0x00007f3686e010fb	(chrome -browser_main.cc:46 )	content::BrowserMain
0x00007f36878957e0	(chrome -content_main_runner.cc:786 )	content::ContentMainRunnerImpl::Run
0x00007f368789435a	(chrome -content_main.cc:20 )	content::ContentMain
0x00007f368648fe21	(chrome -chrome_main.cc:85 )	ChromeMain
0x00007f3683b1efb5	(libc-2.19.so -libc-start.c:292 )	__libc_start_main
0x00007f368648fc64	(chrome + 0x01174c64 )	_start 

alemate@: Could you please take a look at this and confirm if the change is related to https://codereview.chromium.org/2299893002

Thank you!

This bug has not been touched in over a month but is marked as a beta blocker for R55, does this still repro?

Just a heads up that this bug is marked as ReleaseBlock-Beta for R55, and we are looking to promote R55 to beta with the build on Monday evening. 

Thus we need to reevaluate if this bug is really a beta blocker, or get a fix in by Monday afternoon.

If there are no reports on this, or further concerns, perhaps we should remove the blocker label?

Cannot reproduce (this likely has been already fixed).