Failed at least here: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac_chromium_rel_ng/59504

https://logs.chromium.org/v/?s=chromium%2Fbuildbucket%2Fcr-buildbucket.appspot.com%2F8945005677182182256%2F%2B%2Fsteps%2Finteractive_ui_tests__with_patch_%2F0%2Flogs%2FKeyboardLockInteractiveBrowserTest.RequestedButNotActiveInBrowserFullscreen%2F0

[ RUN      ] KeyboardLockInteractiveBrowserTest.RequestedButNotActiveInBrowserFullscreen
[71157:3331:0531/071516.131957:WARNING:notification_platform_bridge_mac.mm(510)] AlertNotificationService: XPC connection invalidated.
2018-05-31 07:15:16.238 interactive_ui_tests[71157:723349] *** Owner supplied to -[NSTrackingArea initWithRect:options:owner:userInfo:] referenced a deallocating object. Tracking area behavior is undefined. Break on NSTrackingAreaDeallocatingOwnerError to debug.
[71162:775:0531/071516.241102:WARNING:vt_video_decode_accelerator_mac.cc(193)] Failed to create VTDecompressionSession: Error Domain=NSOSStatusErrorDomain Code=-8973 "codecOpenErr" (-8973)
[71162:775:0531/071516.241652:WARNING:vt_video_decode_accelerator_mac.cc(215)] Hardware decoding with VideoToolbox is not supported
[71162:775:0531/071516.323089:ERROR:vt_video_encode_accelerator_mac.cc(516)]  VTCompressionSessionCreate failed: -12908
[71157:775:0531/071516.551369:WARNING:gaia_auth_fetcher.cc(902)] Could not reach Google Accounts servers: errno -11
[71157:130567:0531/071517.209905:WARNING:embedded_test_server.cc(229)] Request not handled. Returning 404: /favicon.ico
../../chrome/browser/ui/keyboard_lock_interactive_browsertest.cc:340: Failure
Value of: IsInBrowserFullscreen()
  Actual: false
Expected: true
Stack trace:
0   interactive_ui_tests                0x00000001048c9c6b testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop(int) + 91
1   interactive_ui_tests                0x00000001048c9629 testing::internal::AssertHelper::operator=(testing::Message const&) const + 89
2   interactive_ui_tests                0x000000010478bd80 KeyboardLockInteractiveBrowserTest_RequestedButNotActiveInBrowserFullscreen_Test::RunTestOnMainThread() + 1232
3   interactive_ui_tests                0x000000010839807f content::BrowserTestBase::ProxyRunTestOnMainThreadLoop() + 591
4   interactive_ui_tests                0x0000000107c80f71 ChromeBrowserMainParts::PreMainMessageLoopRunImpl() + 4641
5   interactive_ui_tests                0x0000000107c7fc4e ChromeBrowserMainParts::PreMainMessageLoopRun() + 62
6   interactive_ui_tests                0x0000000105b34ad3 content::BrowserMainLoop::PreMainMessageLoopRun() + 67
7   interactive_ui_tests                0x00000001060b0a85 content::StartupTaskRunner::RunAllTasksNow() + 117
8   interactive_ui_tests                0x0000000105b332b2 content::BrowserMainLoop::CreateStartupTasks() + 914
9   interactive_ui_tests                0x0000000105b37765 content::BrowserMainRunnerImpl::Initialize(content::MainFunctionParams const&, std::__1::unique_ptr<content::BrowserProcessSubThread, std::__1::default_delete<content::BrowserProcessSubThread> >) + 101
10  interactive_ui_tests                0x0000000105b310e5 content::BrowserMain(content::MainFunctionParams const&, std::__1::unique_ptr<content::BrowserProcessSubThread, std::__1::default_delete<content::BrowserProcessSubThread> >) + 229
11  interactive_ui_tests                0x0000000107a51493 content::RunBrowserProcessMain(content::MainFunctionParams const&, content::ContentMainDelegate*, std::__1::unique_ptr<content::BrowserProcessSubThread, std::__1::default_delete<content::BrowserProcessSubThread> >) + 195
12  interactive_ui_tests                0x0000000107a5259e content::ContentMainRunnerImpl::Run() + 686
13  interactive_ui_tests                0x000000010a2921c7 service_manager::Main(service_manager::MainParams const&) + 2855
14  interactive_ui_tests                0x0000000107a513a4 content::ContentMain(content::ContentMainParams const&) + 68
15  interactive_ui_tests                0x0000000108397c0c content::BrowserTestBase::SetUp() + 3212
16  interactive_ui_tests                0x0000000107c08fc5 InProcessBrowserTest::SetUp() + 613
[71157:775:0531/071517.626017:WARNING:gaia_auth_fetcher.cc(902)] Could not reach Google Accounts servers: errno -11
[71157:42499:0531/071517.741815:WARNING:discardable_shared_memory_manager.cc(431)] Some MojoDiscardableSharedMemoryManagerImpls are still alive. They will be leaked.
[71157:775:0531/071517.747907:WARNING:url_request_context_getter.cc(43)] URLRequestContextGetter leaking due to no owning thread.
[71157:775:0531/071517.749191:WARNING:pref_notifier_impl.cc(23)] Pref observer found at shutdown.
[71157:775:0531/071517.749248:WARNING:pref_notifier_impl.cc(23)] Pref observer found at shutdown.
[  FAILED  ] KeyboardLockInteractiveBrowserTest.RequestedButNotActiveInBrowserFullscreen, where TypeParam =  and GetParam() =  (1835 ms)


The test is brand new: https://chromium.googlesource.com/chromium/src/+/a7235f97495cea57f36fbb750ae3e07fcd90b657


If it takes a while to investigate, please disable the test in the meantime, or since it's new, revert.