I don't see how it's failing, but your crrev.com/c/1272636 seems quite related.

Bot: https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.13%20Tests%20%28dbg%29

Failure:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.13%20Tests%20%28dbg%29/5869

Log snippet:
[ RUN      ] SystemWebAppManagerIntegrationTest.WithManifest
[22577:775:1022/230913.465049:ERROR:external_web_apps.cc(207)] Scanning 
[22577:2819:1022/230913.482338:WARNING:notification_platform_bridge_mac.mm(512)] AlertNotificationService: XPC connection invalidated.
objc[22586]: Class RTCDispatcher is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x140443298) and /b/s/w/ir/out/Debug/browser_tests (0x11b848340). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCEncodedImage is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1404432e8) and /b/s/w/ir/out/Debug/browser_tests (0x11b848390). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCRtpFragmentationHeader is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x140443338) and /b/s/w/ir/out/Debug/browser_tests (0x11b8483e0). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCVideoCapturer is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x140443360) and /b/s/w/ir/out/Debug/browser_tests (0x11b848408). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCVideoCodecInfo is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1404433b0) and /b/s/w/ir/out/Debug/browser_tests (0x11b848458). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCVideoEncoderQpThresholds is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x140443400) and /b/s/w/ir/out/Debug/browser_tests (0x11b8484a8). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCVideoEncoderSettings is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x140443478) and /b/s/w/ir/out/Debug/browser_tests (0x11b848520). One of the two will be used. Which one is undefined.
objc[22586]: Class RTCVideoFrame is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1404434a0) and /b/s/w/ir/out/Debug/browser_tests (0x11b848548). One of the two will be used. Which one is undefined.
[22586:775:1022/230914.012004:WARNING:vt_video_decode_accelerator_mac.cc(193)] Failed to create VTDecompressionSession: Error Domain=NSOSStatusErrorDomain Code=-8973 "codecOpenErr" (-8973)
[22586:775:1022/230914.012616:WARNING:vt_video_decode_accelerator_mac.cc(215)] Hardware decoding with VideoToolbox is not supported
[22577:775:1022/230914.066452:ERROR:delegated_frame_host.cc(164)] Not implemented reached in void content::DelegatedFrameHost::SetNeedsBeginFrames(bool)
[22586:775:1022/230914.118329:ERROR:vt_video_encode_accelerator_mac.cc(513)]  VTCompressionSessionCreate failed: -12908
objc[22598]: Class RTCDispatcher is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b298) and /b/s/w/ir/out/Debug/browser_tests (0x11d513340). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCEncodedImage is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b2e8) and /b/s/w/ir/out/Debug/browser_tests (0x11d513390). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCRtpFragmentationHeader is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b338) and /b/s/w/ir/out/Debug/browser_tests (0x11d5133e0). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCVideoCapturer is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b360) and /b/s/w/ir/out/Debug/browser_tests (0x11d513408). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCVideoCodecInfo is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b3b0) and /b/s/w/ir/out/Debug/browser_tests (0x11d513458). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCVideoEncoderQpThresholds is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b400) and /b/s/w/ir/out/Debug/browser_tests (0x11d5134a8). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCVideoEncoderSettings is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b478) and /b/s/w/ir/out/Debug/browser_tests (0x11d513520). One of the two will be used. Which one is undefined.
objc[22598]: Class RTCVideoFrame is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x14211b4a0) and /b/s/w/ir/out/Debug/browser_tests (0x11d513548). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCDispatcher is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb0298) and /b/s/w/ir/out/Debug/browser_tests (0x112e80340). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCEncodedImage is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb02e8) and /b/s/w/ir/out/Debug/browser_tests (0x112e80390). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCRtpFragmentationHeader is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb0338) and /b/s/w/ir/out/Debug/browser_tests (0x112e803e0). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCVideoCapturer is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb0360) and /b/s/w/ir/out/Debug/browser_tests (0x112e80408). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCVideoCodecInfo is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb03b0) and /b/s/w/ir/out/Debug/browser_tests (0x112e80458). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCVideoEncoderQpThresholds is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb0400) and /b/s/w/ir/out/Debug/browser_tests (0x112e804a8). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCVideoEncoderSettings is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb0478) and /b/s/w/ir/out/Debug/browser_tests (0x112e80520). One of the two will be used. Which one is undefined.
objc[22599]: Class RTCVideoFrame is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13bbb04a0) and /b/s/w/ir/out/Debug/browser_tests (0x112e80548). One of the two will be used. Which one is undefined.
[22577:775:1022/230914.484353:WARNING:gaia_auth_fetcher.cc(858)] Could not reach Google Accounts servers: errno -11
objc[22601]: Class RTCDispatcher is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea298) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e4340). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCEncodedImage is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea2e8) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e4390). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCRtpFragmentationHeader is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea338) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e43e0). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCVideoCapturer is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea360) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e4408). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCVideoCodecInfo is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea3b0) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e4458). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCVideoEncoderQpThresholds is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea400) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e44a8). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCVideoEncoderSettings is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea478) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e4520). One of the two will be used. Which one is undefined.
objc[22601]: Class RTCVideoFrame is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1400ea4a0) and /b/s/w/ir/out/Debug/browser_tests (0x11b4e4548). One of the two will be used. Which one is undefined.
[22586:775:1022/230915.310399:WARNING:ca_layer_tree_coordinator.mm(55)] Blank frame: No overlays or CALayers
[22577:775:1022/230915.367962:ERROR:delegated_frame_host.cc(164)] Not implemented reached in void content::DelegatedFrameHost::SetNeedsBeginFrames(bool)
[22577:775:1022/230915.457845:WARNING:gaia_auth_fetcher.cc(858)] Could not reach Google Accounts servers: errno -11
objc[22606]: Class RTCDispatcher is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf298) and /b/s/w/ir/out/Debug/browser_tests (0x116cd7340). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCEncodedImage is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf2e8) and /b/s/w/ir/out/Debug/browser_tests (0x116cd7390). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCRtpFragmentationHeader is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf338) and /b/s/w/ir/out/Debug/browser_tests (0x116cd73e0). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCDispatcher is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f5298) and /b/s/w/ir/out/Debug/browser_tests (0x1108f6340). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCVideoCapturer is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf360) and /b/s/w/ir/out/Debug/browser_tests (0x116cd7408). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCEncodedImage is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f52e8) and /b/s/w/ir/out/Debug/browser_tests (0x1108f6390). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCVideoCodecInfo is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf3b0) and /b/s/w/ir/out/Debug/browser_tests (0x116cd7458). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCRtpFragmentationHeader is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f5338) and /b/s/w/ir/out/Debug/browser_tests (0x1108f63e0). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCVideoEncoderQpThresholds is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf400) and /b/s/w/ir/out/Debug/browser_tests (0x116cd74a8). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCVideoCapturer is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f5360) and /b/s/w/ir/out/Debug/browser_tests (0x1108f6408). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCVideoEncoderSettings is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf478) and /b/s/w/ir/out/Debug/browser_tests (0x116cd7520). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCVideoCodecInfo is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f53b0) and /b/s/w/ir/out/Debug/browser_tests (0x1108f6458). One of the two will be used. Which one is undefined.
objc[22606]: Class RTCVideoFrame is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x13b8cf4a0) and /b/s/w/ir/out/Debug/browser_tests (0x116cd7548). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCVideoEncoderQpThresholds is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f5400) and /b/s/w/ir/out/Debug/browser_tests (0x1108f64a8). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCVideoEncoderSettings is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f5478) and /b/s/w/ir/out/Debug/browser_tests (0x1108f6520). One of the two will be used. Which one is undefined.
objc[22607]: Class RTCVideoFrame is implemented in both /b/s/w/ir/out/Debug/./libcontent.dylib (0x1354f54a0) and /b/s/w/ir/out/Debug/browser_tests (0x1108f6548). One of the two will be used. Which one is undefined.
[22577:775:1022/230916.520472:FATAL:extension_util.cc(340)] Check failed: base::FeatureList::IsEnabled(::features::kDesktopPWAWindowing). 
0   libbase.dylib                       0x00000001273be89e base::debug::StackTrace::StackTrace(unsigned long) + 174
1   libbase.dylib                       0x00000001273be95d base::debug::StackTrace::StackTrace(unsigned long) + 29
2   libbase.dylib                       0x0000000126f8dd4a base::debug::StackTrace::StackTrace() + 26
3   libbase.dylib                       0x0000000126ffbd3d logging::LogMessage::~LogMessage() + 461
4   libbase.dylib                       0x0000000126ff98d5 logging::LogMessage::~LogMessage() + 21
5   browser_tests                       0x000000010fbc5de2 extensions::util::GetInstalledPwaForUrl(content::BrowserContext*, GURL const&, base::Optional<extensions::LaunchContainer>) + 194
6   browser_tests                       0x000000010ac71fca web_app::SystemWebAppManagerIntegrationTest_WithManifest_Test::RunTestOnMainThread() + 3418
7   browser_tests                       0x000000010cc55e8f content::BrowserTestBase::ProxyRunTestOnMainThreadLoop() + 2111
8   browser_tests                       0x000000010cc58e1d void base::internal::FunctorTraits<void (content::BrowserTestBase::*)(), void>::Invoke<void (content::BrowserTestBase::*)(), content::BrowserTestBase*>(void (content::BrowserTestBase::*)(), content::BrowserTestBase*&&) + 125
9   browser_tests                       0x000000010cc58d64 void base::internal::InvokeHelper<false, void>::MakeItSo<void (content::BrowserTestBase::* const&)(), content::BrowserTestBase*>(void (content::BrowserTestBase::* const&&&)(), content::BrowserTestBase*&&) + 68
10  browser_tests                       0x000000010cc58cf3 void base::internal::Invoker<base::internal::BindState<void (content::BrowserTestBase::*)(), base::internal::UnretainedWrapper<content::BrowserTestBase> >, void ()>::RunImpl<void (content::BrowserTestBase::* const&)(), std::__1::tuple<base::internal::UnretainedWrapper<content::BrowserTestBase> > const&, 0ul>(void (content::BrowserTestBase::* const&&&)(), std::__1::tuple<base::internal::UnretainedWrapper<content::BrowserTestBase> > const&&&, std::__1::integer_sequence<unsigned long, 0ul>) + 99
11  browser_tests                       0x000000010cc58c1c base::internal::Invoker<base::internal::BindState<void (content::BrowserTestBase::*)(), base::internal::UnretainedWrapper<content::BrowserTestBase> >, void ()>::Run(base::internal::BindStateBase*) + 44
12  browser_tests                       0x000000010416bded base::RepeatingCallback<void ()>::Run() const & + 61
13  browser_tests                       0x000000010b024261 ChromeBrowserMainParts::PreMainMessageLoopRunImpl() + 9377
14  browser_tests                       0x000000010b021d0a ChromeBrowserMainParts::PreMainMessageLoopRun() + 250
15  libcontent.dylib                    0x00000001345d477b content::BrowserMainLoop::PreMainMessageLoopRun() + 331
16  libcontent.dylib                    0x00000001345db1dd int base::internal::FunctorTraits<int (content::BrowserMainLoop::*)(), void>::Invoke<int (content::BrowserMainLoop::*)(), content::BrowserMainLoop*>(int (content::BrowserMainLoop::*)(), content::BrowserMainLoop*&&) + 125
17  libcontent.dylib                    0x00000001345db124 int base::internal::InvokeHelper<false, int>::MakeItSo<int (content::BrowserMainLoop::* const&)(), content::BrowserMainLoop*>(int (content::BrowserMainLoop::* const&&&)(), content::BrowserMainLoop*&&) + 68
18  libcontent.dylib                    0x00000001345db0b3 int base::internal::Invoker<base::internal::BindState<int (content::BrowserMainLoop::*)(), base::internal::UnretainedWrapper<content::BrowserMainLoop> >, int ()>::RunImpl<int (content::BrowserMainLoop::* const&)(), std::__1::tuple<base::internal::UnretainedWrapper<content::BrowserMainLoop> > const&, 0ul>(int (content::BrowserMainLoop::* const&&&)(), std::__1::tuple<base::internal::UnretainedWrapper<content::BrowserMainLoop> > const&&&, std::__1::integer_sequence<unsigned long, 0ul>) + 99
19  libcontent.dylib                    0x00000001345dafac base::internal::Invoker<base::internal::BindState<int (content::BrowserMainLoop::*)(), base::internal::UnretainedWrapper<content::BrowserMainLoop> >, int ()>::Run(base::internal::BindStateBase*) + 44
20  libcontent.dylib                    0x000000013524ba7d base::RepeatingCallback<int ()>::Run() const & + 61
21  libcontent.dylib                    0x0000000135d335f0 content::StartupTaskRunner::RunAllTasksNow() + 528
22  libcontent.dylib                    0x00000001345cfd80 content::BrowserMainLoop::CreateStartupTasks() + 2768
23  libcontent.dylib                    0x00000001345df3fd content::BrowserMainRunnerImpl::Initialize(content::MainFunctionParams const&) + 3133
24  libcontent.dylib                    0x00000001345c6214 content::BrowserMain(content::MainFunctionParams const&) + 548
25  libcontent.dylib                    0x00000001377d4161 content::RunBrowserProcessMain(content::MainFunctionParams const&, content::ContentMainDelegate*) + 289
26  libcontent.dylib                    0x00000001377d7b78 content::ContentMainRunnerImpl::Run(bool) + 5320
27  libcontent.dylib                    0x00000001377cde0c content::ContentServiceManagerMainDelegate::RunEmbedderProcess() + 76
28  libembedder.dylib                   0x0000000176f4e127 service_manager::Main(service_manager::MainParams const&) + 3751
29  libcontent.dylib                    0x00000001377d3ff9 content::ContentMain(content::ContentMainParams const&) + 89
30  browser_tests                       0x000000010cc552da content::BrowserTestBase::SetUp() + 8602
31  browser_tests                       0x000000010adb00ce InProcessBrowserTest::SetUp() + 2670
32  browser_tests                       0x000000010acdd69c extensions::ExtensionBrowserTest::SetUp() + 236
33  browser_tests                       0x000000010744a13e void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 126
34  browser_tests                       0x000000010741b642 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 114
35  browser_tests                       0x000000010741b524 testing::Test::Run() + 116
36  browser_tests                       0x000000010741c515 testing::TestInfo::Run() + 213
37  browser_tests                       0x000000010741dbcf testing::TestCase::Run() + 239
38  browser_tests                       0x0000000107433f96 testing::internal::UnitTestImpl::RunAllTests() + 886
39  browser_tests                       0x000000010744d47e bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) + 126
40  browser_tests                       0x0000000107433ba2 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) + 114
41  browser_tests                       0x0000000107433a7b testing::UnitTest::Run() + 395
42  browser_tests                       0x000000010ae1b921 RUN_ALL_TESTS() + 17
43  browser_tests                       0x000000010ae1abeb base::TestSuite::Run() + 363
44  browser_tests                       0x000000010acb3944 ChromeTestSuiteRunner::RunTestSuite(int, char**) + 100
45  browser_tests                       0x000000010acb3ad3 ChromeTestLauncherDelegate::RunTestSuite(int, char**) + 51
46  browser_tests                       0x000000010cd35414 content::LaunchTests(content::TestLauncherDelegate*, unsigned long, int, char**) + 1380
47  browser_tests                       0x000000010acb51ed LaunchChromeTests(unsigned long, content::TestLauncherDelegate*, int, char**) + 2013
48  browser_tests                       0x000000010acb3009 main + 153
49  libdyld.dylib                       0x00007fff62ebd015 start + 1
50  ???                                 0x000000000000000c 0x0 + 12

[28/389] SystemWebAppManagerIntegrationTest.WithManifest (CRASHED)