I get this DCHECK on almost any navigation.
iOS simulator - iOS12 - iPhone 7
DCHECK in mojo::DataPipe::DataPipe
called from network::URLLoader::OnResponseStarted


[0928/172704.067941:FATAL:data_pipe.h(166)] Check failed: MOJO_RESULT_OK == result (0 vs. 8)
[0928/172714.651465:FATAL:handle.h(99)] Check failed: handle_.is_valid(). 
[0928/172715.996420:FATAL:handle.h(99)] Check failed: handle_.is_valid(). 
[0928/172717.810251:FATAL:simple_url_loader.cc(466)] Check failed: MOJO_RESULT_FAILED_PRECONDITION == result (9 vs. 3)
[0928/172743.680272:ERROR:platform_shared_memory_region_posix.cc(247)] open("/Users/olivierrobin/Library/Developer/CoreSimulator/Devices/D5A02D81-FB7D-471E-8B8B-98871904AD4A/data/Containers/Data/Application/4893F9EE-4654-4C92-8E64-52812E81670D/tmp/.com.google.chrome.ios.herebedragons.MR2lyU", O_RDONLY) failed: Too many open files in system (23)
[0928/172743.680554:FATAL:data_pipe.h(173)] Check failed: MOJO_RESULT_OK == result (0 vs. 8)
(lldb) bt
* thread #13, name = 'Web_IOThread', stop reason = EXC_BREAKPOINT (code=EXC_I386_BPT, subcode=0x0)
  * frame #0: 0x000000010da07854 Chromium`base::debug::BreakDebugger() at debugger_posix.cc:274
    frame #1: 0x000000010d727bd2 Chromium`logging::LogMessage::~LogMessage(this=0x000070000d568970) at logging.cc:856
    frame #2: 0x000000010d7244b5 Chromium`logging::LogMessage::~LogMessage(this=0x000070000d568970) at logging.cc:584
    frame #3: 0x0000000110c4fb49 Chromium`mojo::DataPipe::DataPipe(this=0x000070000d568af8, options=0x000070000d568b00) at data_pipe.h:173
    frame #4: 0x0000000110c4fa2d Chromium`mojo::DataPipe::DataPipe(this=0x000070000d568af8, options=0x000070000d568b00) at data_pipe.h:169
    frame #5: 0x0000000110c4f91c Chromium`mojo::DataPipe::DataPipe(this=0x000070000d568eb0, capacity_num_bytes=524288) at data_pipe.h:162
    frame #6: 0x0000000110c4c87b Chromium`mojo::DataPipe::DataPipe(this=0x000070000d568eb0, capacity_num_bytes=524288) at data_pipe.h:156
    frame #7: 0x0000000110c4b323 Chromium`network::URLLoader::OnResponseStarted(this=0x00007fbdb4d832d0, url_request=0x00007fbdb58d8800, net_error=0) at url_loader.cc:687
    frame #8: 0x000000010ea42220 Chromium`net::URLRequest::NotifyResponseStarted(this=0x00007fbdb58d8800, status=0x000070000d569ad8) at url_request.cc:857
    frame #9: 0x000000010ea7e901 Chromium`net::URLRequestJob::NotifyHeadersComplete(this=0x00007fbdb58e6400) at url_request_job.cc:494
    frame #10: 0x000000010ea6ab82 Chromium`net::URLRequestHttpJob::NotifyHeadersComplete(this=0x00007fbdb58e6400) at url_request_http_job.cc:523
    frame #11: 0x000000010ea6e9e6 Chromium`net::URLRequestHttpJob::SaveCookiesAndNotifyHeadersComplete(this=0x00007fbdb58e6400, result=0) at url_request_http_job.cc:810
    frame #12: 0x000000010ea6cf8b Chromium`net::URLRequestHttpJob::OnStartCompleted(this=0x00007fbdb58e6400, result=0) at url_request_http_job.cc:1034
    frame #13: 0x000000010ea76b7f Chromium`void base::internal::FunctorTraits<void (net::URLRequestHttpJob::*)(int), void>::Invoke<void (method=b0 c7 a6 0e 01 00 00 00 00 00 00 00 00 00 00 00, receiver_ptr=0x000070000d56ab70, args=0x000070000d56abec)(int), net::URLRequestHttpJob*, int>(void (net::URLRequestHttpJob::*)(int), net::URLRequestHttpJob*&&, int&&) at bind_internal.h:516
    frame #14: 0x000000010ea77d7f Chromium`void base::internal::InvokeHelper<false, void>::MakeItSo<void (functor=0x0000600000db9fa0, args=0x000070000d56ab70, args=0x000070000d56abec)(int), net::URLRequestHttpJob*, int>(void (net::URLRequestHttpJob::* const&&&)(int), net::URLRequestHttpJob*&&, int&&) at bind_internal.h:616
    frame #15: 0x000000010ea77d15 Chromium`void base::internal::Invoker<base::internal::BindState<void (net::URLRequestHttpJob::*)(int), base::internal::UnretainedWrapper<net::URLRequestHttpJob> >, void (int)>::RunImpl<void (functor=0x0000600000db9fa0, bound=size=1, (null)=std::__1::index_sequence<0UL> @ 0x000070000d56ab90, unbound_args=0x000070000d56abec)(int), std::__1::tuple<base::internal::UnretainedWrapper<net::URLRequestHttpJob> > const&, 0ul>(void (net::URLRequestHttpJob::* const&&&)(int), std::__1::tuple<base::internal::UnretainedWrapper<net::URLRequestHttpJob> > const&&&, std::__1::integer_sequence<unsigned long, 0ul>, int&&) at bind_internal.h:689
    frame #16: 0x000000010ea77c9b Chromium`base::internal::Invoker<base::internal::BindState<void (net::URLRequestHttpJob::*)(int), base::internal::UnretainedWrapper<net::URLRequestHttpJob> >, void (int)>::Run(base=0x0000600000db9f80, unbound_args=0) at bind_internal.h:671
    frame #17: 0x000000010b4dcdcf Chromium`base::OnceCallback<void (int)>::Run(this=0x000070000d56ad78, args=0) && at callback.h:99
    frame #18: 0x000000010e3887fb Chromium`net::HttpCache::Transaction::DoLoop(this=0x00007fbdb58d0a00, result=0) at http_cache_transaction.cc:1033
    frame #19: 0x000000010e38484b Chromium`net::HttpCache::Transaction::OnIOComplete(this=0x00007fbdb58d0a00, result=0) at http_cache_transaction.cc:3562
    frame #20: 0x000000010e3a70a1 Chromium`void base::internal::FunctorTraits<void (net::HttpCache::Transaction::*)(int), void>::Invoke<void (method=30 48 38 0e 01 00 00 00 00 00 00 00 00 00 00 00, receiver_ptr=0x0000600000db90b0, args=0x000070000d56d5fc)(int), base::WeakPtr<net::HttpCache::Transaction> const&, int>(void (net::HttpCache::Transaction::*)(int), base::WeakPtr<net::HttpCache::Transaction> const&&&, int&&) at bind_internal.h:516
    frame #21: 0x000000010e3a6fa5 Chromium`void base::internal::InvokeHelper<true, void>::MakeItSo<void (functor=0x0000600000db90a0, weak_ptr=0x0000600000db90b0, args=0x000070000d56d5fc)(int), base::WeakPtr<net::HttpCache::Transaction> const&, int>(void (net::HttpCache::Transaction::* const&&&)(int), base::WeakPtr<net::HttpCache::Transaction> const&&&, int&&) at bind_internal.h:636
    frame #22: 0x000000010e3a6f20 Chromium`void base::internal::Invoker<base::internal::BindState<void (net::HttpCache::Transaction::*)(int), base::WeakPtr<net::HttpCache::Transaction> >, void (int)>::RunImpl<void (functor=0x0000600000db90a0, bound=size=1, (null)=std::__1::index_sequence<0UL> @ 0x000070000d56d5a0, unbound_args=0x000070000d56d5fc)(int), std::__1::tuple<base::WeakPtr<net::HttpCache::Transaction> > const&, 0ul>(void (net::HttpCache::Transaction::* const&&&)(int), std::__1::tuple<base::WeakPtr<net::HttpCache::Transaction> > const&&&, std::__1::integer_sequence<unsigned long, 0ul>, int&&) at bind_internal.h:689
    frame #23: 0x000000010e3a6e4b Chromium`base::internal::Invoker<base::internal::BindState<void (net::HttpCache::Transaction::*)(int), base::WeakPtr<net::HttpCache::Transaction> >, void (int)>::Run(base=0x0000600000db9080, unbound_args=0) at bind_internal.h:671
    frame #24: 0x000000010b4dcdcf Chromium`base::OnceCallback<void (int)>::Run(this=0x00007fbdbab517d8, args=0) && at callback.h:99
    frame #25: 0x000000010e2248ca Chromium`disk_cache::BackendIO::RunCallback(this=0x00007fbdbab51750, result=0) at in_flight_backend_io.cc:93
    frame #26: 0x000000010e226ea5 Chromium`disk_cache::InFlightBackendIO::OnOperationComplete(this=0x00007fbdbf9001b0, operation=0x00007fbdbab51750, cancel=false) at in_flight_backend_io.cc:578
    frame #27: 0x000000010e2286c6 Chromium`disk_cache::InFlightIO::InvokeCallback(this=0x00007fbdbf9001b0, operation=0x00007fbdbab51750, cancel_task=false) at in_flight_io.cc:101
    frame #28: 0x000000010e228251 Chromium`disk_cache::BackgroundIO::OnIOSignalled(this=0x00007fbdbab51750) at in_flight_io.cc:25
    frame #29: 0x000000010e22a77f Chromium`void base::internal::FunctorTraits<void (disk_cache::BackgroundIO::*)(), void>::Invoke<void (method=20 82 22 0e 01 00 00 00 00 00 00 00 00 00 00 00, receiver_ptr=0x00006000003ebd30)(), scoped_refptr<disk_cache::BackgroundIO> const&>(void (disk_cache::BackgroundIO::*)(), scoped_refptr<disk_cache::BackgroundIO> const&&&) at bind_internal.h:516
    frame #30: 0x000000010e22a6c4 Chromium`void base::internal::InvokeHelper<false, void>::MakeItSo<void (functor=0x00006000003ebd20, args=0x00006000003ebd30)(), scoped_refptr<disk_cache::BackgroundIO> const&>(void (disk_cache::BackgroundIO::* const&&&)(), scoped_refptr<disk_cache::BackgroundIO> const&&&) at bind_internal.h:616
    frame #31: 0x000000010e22a670 Chromium`void base::internal::Invoker<base::internal::BindState<void (disk_cache::BackgroundIO::*)(), scoped_refptr<disk_cache::BackgroundIO> >, void ()>::RunImpl<void (functor=0x00006000003ebd20, bound=size=1, (null)=std::__1::index_sequence<0UL> @ 0x000070000d56db88)(), std::__1::tuple<scoped_refptr<disk_cache::BackgroundIO> > const&, 0ul>(void (disk_cache::BackgroundIO::* const&&&)(), std::__1::tuple<scoped_refptr<disk_cache::BackgroundIO> > const&&&, std::__1::integer_sequence<unsigned long, 0ul>) at bind_internal.h:689
    frame #32: 0x000000010e22a5ac Chromium`base::internal::Invoker<base::internal::BindState<void (disk_cache::BackgroundIO::*)(), scoped_refptr<disk_cache::BackgroundIO> >, void ()>::Run(base=0x00006000003ebd00) at bind_internal.h:671
    frame #33: 0x000000010bb156ee Chromium`base::OnceCallback<void ()>::Run(this=0x000070000d56e338) && at callback.h:99
    frame #34: 0x000000010d6e1903 Chromium`base::debug::TaskAnnotator::RunTask(this=0x0000600003375188, queue_function="MessageLoop::PostTask", pending_task=0x000070000d56e338) at task_annotator.cc:101
    frame #35: 0x000000010d7478cf Chromium`base::MessageLoop::RunTask(this=0x00007fbdb82026e0, pending_task=0x000070000d56e338) at message_loop.cc:434
    frame #36: 0x000000010d747daf Chromium`base::MessageLoop::DeferOrRunPendingTask(this=0x00007fbdb82026e0, pending_task=PendingTask @ 0x000070000d56e338) at message_loop.cc:445
    frame #37: 0x000000010d74826a Chromium`base::MessageLoop::DoWork(this=0x00007fbdb82026e0) at message_loop.cc:517
    frame #38: 0x000000010da3cf34 Chromium`base::MessagePumpCFRunLoopBase::RunWork(this=0x00007fbdb4f03e90) at message_pump_mac.mm:455
    frame #39: 0x000000010da3cecc Chromium`::___ZN4base24MessagePumpCFRunLoopBase13RunWorkSourceEPv_block_invoke(.block_descriptor=0x000070000d56e598) at message_pump_mac.mm:432
    frame #40: 0x000000010da2f451 Chromium`base::mac::CallWithEHFrame(block=0x000000010da3ceb0) block_pointer) at call_with_eh_frame.cc:18
    frame #41: 0x000000010da3c187 Chromium`base::MessagePumpCFRunLoopBase::RunWorkSource(info=0x00007fbdb4f03e90) at message_pump_mac.mm:431
    frame #42: 0x00000001199a3b31 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
    frame #43: 0x00000001199a33a3 CoreFoundation`__CFRunLoopDoSources0 + 243
    frame #44: 0x000000011999da4f CoreFoundation`__CFRunLoopRun + 1263
    frame #45: 0x000000011999d221 CoreFoundation`CFRunLoopRunSpecific + 625
    frame #46: 0x000000011a923522 Foundation`-[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 277
    frame #47: 0x000000010da3d949 Chromium`base::MessagePumpNSRunLoop::DoRun(this=0x00007fbdb4f03e90, delegate=0x00007fbdb82026e0) at message_pump_mac.mm:729
    frame #48: 0x000000010da3b915 Chromium`base::MessagePumpCFRunLoopBase::Run(this=0x00007fbdb4f03e90, delegate=0x00007fbdb82026e0) at message_pump_mac.mm:184
    frame #49: 0x000000010d746f7c Chromium`base::MessageLoop::Run(this=0x00007fbdb82026e0, application_tasks_allowed=true) at message_loop.cc:386
    frame #50: 0x000000010d7fbcce Chromium`base::RunLoop::Run(this=0x000070000d570838) at run_loop.cc:102
    frame #51: 0x000000010d915b19 Chromium`base::Thread::Run(this=0x00007fbdb8207ec0, run_loop=0x000070000d570838) at thread.cc:262
    frame #52: 0x000000010bfd0287 Chromium`web::WebThreadImpl::IOThreadRun(this=0x00007fbdb8207ec0, run_loop=0x000070000d570838) at web_thread_impl.cc:248
    frame #53: 0x000000010bfd0426 Chromium`web::WebThreadImpl::Run(this=0x00007fbdb8207ec0, run_loop=0x000070000d570838) at web_thread_impl.cc:261
    frame #54: 0x000000010d916885 Chromium`base::Thread::ThreadMain(this=0x00007fbdb8207ec0) at thread.cc:357
    frame #55: 0x000000010da2d693 Chromium`base::(anonymous namespace)::ThreadFunc(params=0x0000600001a46440) at platform_thread_posix.cc:80
    frame #56: 0x0000000123303661 libsystem_pthread.dylib`_pthread_body + 340
    frame #57: 0x000000012330350d libsystem_pthread.dylib`_pthread_start + 377
    frame #58: 0x0000000123302bf9 libsystem_pthread.dylib`thread_start + 13
(lldb) 
 

Deleted: Screen Shot 2018-09-28 at 5.28.09 PM.png 298 KB

	Screen Shot 2018-09-28 at 5.28.09 PM.png 298 KB View Download