Sometimes this happens:

[3090:7175:0123/072313.683347:FATAL:user_input_monitor.cc(22)] Check failed: 0u == key_press_counter_references_ (0 vs. 1)
0   browser_tests                       0x0000000117bb597c base::debug::StackTrace::StackTrace(unsigned long) + 28
1   browser_tests                       0x0000000117c12617 logging::LogMessage::~LogMessage() + 695
2   browser_tests                       0x000000011208f051 media::UserInputMonitor::~UserInputMonitor() + 337
3   browser_tests                       0x00000001120b696e media::(anonymous namespace)::UserInputMonitorMac::~UserInputMonitorMac() + 14
4   browser_tests                       0x000000011330e40c content::BrowserMainLoop::~BrowserMainLoop() + 1852
5   browser_tests                       0x000000011330eb6e content::BrowserMainLoop::~BrowserMainLoop() + 14
6   browser_tests                       0x00000001133230f4 content::BrowserMainRunnerImpl::Shutdown() + 1300
7   browser_tests                       0x000000011330d31e content::BrowserMain(content::MainFunctionParams const&) + 718
8   browser_tests                       0x0000000117ae59ce content::RunNamedProcessTypeMain(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, content::MainFunctionParams const&, content::ContentMainDelegate*) + 1310
9   browser_tests                       0x0000000117ae74ea content::ContentMainRunnerImpl::Run() + 1354
10  browser_tests                       0x000000011e4717fe service_manager::Main(service_manager::MainParams const&) + 5390
11  browser_tests                       0x0000000117ae53d0 content::ContentMain(content::ContentMainParams const&) + 368
12  browser_tests                       0x00000001192d21c8 content::BrowserTestBase::SetUp() + 5992
13  browser_tests                       0x0000000117e75db5 InProcessBrowserTest::SetUp() + 1301
14  browser_tests                       0x0000000111270f10 testing::Test::Run() + 256
15  browser_tests                       0x0000000111273164 testing::TestInfo::Run() + 900
16  browser_tests                       0x00000001112744a7 testing::TestCase::Run() + 967
17  browser_tests                       0x000000011128c457 testing::internal::UnitTestImpl::RunAllTests() + 2487
18  browser_tests                       0x000000011128b9ea testing::UnitTest::Run() + 298
19  browser_tests                       0x0000000117ec6d19 base::TestSuite::Run() + 505
20  browser_tests                       0x0000000117b85a06 ChromeTestSuiteRunner::RunTestSuite(int, char**) + 198
21  browser_tests                       0x00000001193b9194 content::LaunchTests(content::TestLauncherDelegate*, unsigned long, int, char**) + 1092
22  browser_tests                       0x0000000117b86683 LaunchChromeTests(unsigned long, content::TestLauncherDelegate*, int, char**) + 723
23  browser_tests                       0x0000000117b8585d main + 269
24  libdyld.dylib                       0x00007fff8da1f5fd start + 1
25  ???                                 0x000000000000000b 0x0 + 11

e.g.:

https://uberchromegw.corp.google.com/i/chromium.memory/builders/Mac%20ASan%2064%20Tests%20%281%29/builds/38067