On tip of tree, WebSocketEndpointLockManagerTest.GetInstanceWorks passes for me fine, but when run right after this particular other test, it consistently crashes:

bnc@majom:~/chromium/chromium/src$ out/gn/net_unittests --gtest_filter=HttpStreamFactoryTest.RequestWebSocketBasicHandshakeStreamOverSSL:WebSocketEndpointLockManagerTest.GetInstanceWorks
IMPORTANT DEBUGGING NOTE: batches of tests are run inside their
own process. For debugging a test inside a debugger, use the
--gtest_filter=<your_test_name> flag along with
--single-process-tests.
Using sharding settings from environment. This is shard 0/1
Using 1 parallel jobs.
Note: Google Test filter = HttpStreamFactoryTest.RequestWebSocketBasicHandshakeStreamOverSSL:WebSocketEndpointLockManagerTest.GetInstanceWorks
[==========] Running 2 tests from 2 test cases.
[----------] Global test environment set-up.
[----------] 1 test from HttpStreamFactoryTest
[ RUN      ] HttpStreamFactoryTest.RequestWebSocketBasicHandshakeStreamOverSSL
[       OK ] HttpStreamFactoryTest.RequestWebSocketBasicHandshakeStreamOverSSL (472 ms)
[----------] 1 test from HttpStreamFactoryTest (472 ms total)

[----------] 1 test from WebSocketEndpointLockManagerTest
[ RUN      ] WebSocketEndpointLockManagerTest.GetInstanceWorks
[12968:12968:0222/192510.730831:2440090072973:FATAL:websocket_endpoint_lock_manager_unittest.cc(143)] Check failed: instance_->IsEmpty().
#0 0x7f95ee1c46bd base::debug::StackTrace::StackTrace()
#1 0x7f95ee1c2bac base::debug::StackTrace::StackTrace()
#2 0x7f95ee24ad7a logging::LogMessage::~LogMessage()
#3 0x000002f9f818 net::(anonymous namespace)::WebSocketEndpointLockManagerTest::~WebSocketEndpointLockManagerTest()
#4 0x000002f9f705 net::(anonymous namespace)::WebSocketEndpointLockManagerTest_GetInstanceWorks_Test::~WebSocketEndpointLockManagerTest_GetInstanceWorks_Test()
#5 0x000002f9f729 net::(anonymous namespace)::WebSocketEndpointLockManagerTest_GetInstanceWorks_Test::~WebSocketEndpointLockManagerTest_GetInstanceWorks_Test()
#6 0x000000a2c2fb base::RefCountedThreadSafe<>::DeleteInternal<>()
#7 0x0000028166de _ZN7testing8internal12InvokeHelperIvNSt3__15tupleIJEEEE12InvokeMethodIN3net4test21SimpleSessionNotifierEMS9_FvvEEEvPT_T0_RKS4_
#8 0x000003b9d572 testing::internal::HandleExceptionsInMethodIfSupported<>()
#9 0x000003b88885 testing::TestInfo::Run()
#10 0x000003b892ec testing::TestCase::Run()
#11 0x000003b94e1e testing::internal::UnitTestImpl::RunAllTests()
#12 0x000003ba640e testing::internal::HandleSehExceptionsInMethodIfSupported<>()
#13 0x000003b9ea52 testing::internal::HandleExceptionsInMethodIfSupported<>()
#14 0x000003b94a29 testing::UnitTest::Run()
#15 0x000003d59e81 RUN_ALL_TESTS()
#16 0x000003d56d0b base::TestSuite::Run()
#17 0x0000013272ed _ZN4base8internal13FunctorTraitsIMN3net22NoResultCookieCallbackEFvvEvE6InvokeIPS3_JEEEvS5_OT_DpOT0_
#18 0x000001327264 _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIRKMN3net22NoResultCookieCallbackEFvvEJPS5_EEEvOT_DpOT0_
#19 0x000001327215 _ZN4base8internal7InvokerINS0_9BindStateIMN3net22NoResultCookieCallbackEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE7RunImplIRKS6_RKNSt3__15tupleIJS8_EEEJLm0EEEEvOT_OT0_NSF_16integer_sequenceImJXspT1_EEEE
#20 0x0000013271ac _ZN4base8internal7InvokerINS0_9BindStateIMN3net22NoResultCookieCallbackEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE3RunEPNS0_13BindStateBaseE
#21 0x000000c283fd _ZNKR4base17RepeatingCallbackIFvvEE3RunEv
#22 0x000003d67dd7 base::(anonymous namespace)::LaunchUnitTestsInternal()
#23 0x000003d67c45 base::LaunchUnitTests()
#24 0x0000033dedc3 main
#25 0x7f95ecc942b1 __libc_start_main
#26 0x0000009db02a _start

[12955:12967:0222/192511.188851:2440090531008:ERROR:kill_posix.cc(84)] Unable to terminate process group 12968: No such process (3)
[1/2] HttpStreamFactoryTest.RequestWebSocketBasicHandshakeStreamOverSSL (472 ms)
[2/2] WebSocketEndpointLockManagerTest.GetInstanceWorks (CRASHED)
1 test crashed:
    WebSocketEndpointLockManagerTest.GetInstanceWorks (../../net/socket/websocket_endpoint_lock_manager_unittest.cc:165)
Tests took 4 seconds.