Looks like it first started in https://build.chromium.org/p/chromium.fyi/builders/ClangToTWin%20tester/builds/7725

That build includes a commit which touched the test: https://codereview.chromium.org/2793233002


[ RUN      ] PaintControllerUnderInvalidationTest.MoreDrawingInSubsequence
../../third_party/WebKit/Source/platform/graphics/paint/PaintControllerTest.cpp(2341): error: Death test: TestMoreDrawingInSubsequence()
    Result: died but not with expected error.
  Expected: Check failed: false. Can't find cached display item
Actual msg:
[  DEATH   ] [2740:3716:0413/113648.075:12276841:WARNING:test_suite.cc(236)] Test launcher output path C:\Users\CHROME~2\AppData\Local\Temp\5692_20439\test_results.xml exists. Not adding test launcher result printer.
[  DEATH   ] Backtrace:
[  DEATH   ] 	blink::PaintController::FindOutOfOrderCachedItemForward [0x00BD96C0+126]
[  DEATH   ] 	blink::PaintController::UseCachedDrawingIfPossible [0x00BD88B1+131]
[  DEATH   ] 	blink::DrawRect [0x00449874+40]
[  DEATH   ] 	blink::PaintControllerUnderInvalidationTest::TestMoreDrawingInSubsequence [0x004622FD+471]
[  DEATH   ] 	blink::PaintControllerUnderInvalidationTest_MoreDrawingInSubsequence_Test::TestBody [0x0046209A+170]
[  DEATH   ] 	testing::Test::Run [0x0109C887+193]
[  DEATH   ] 	testing::TestInfo::Run [0x0109CF35+213]
[  DEATH   ] 	testing::TestCase::Run [0x0109D2CC+246]
[  DEATH   ] 	testing::internal::UnitTestImpl::RunAllTests [0x010A0F60+608]
[  DEATH   ] 	testing::UnitTest::Run [0x010A0C26+178]
[  DEATH   ] 	base::TestSuite::Run [0x00CB48D9+113]
[  DEATH   ] 	main [0x005AC20C+312]
[  DEATH   ] 	base::internal::Invoker<base::internal::BindState<void (__cdecl*)(void const *),void const *>,void __cdecl(void)>::RunOnce [0x0051183C+12]
[  DEATH   ] 	base::LaunchUnitTests [0x00CB52CF+395]
[  DEATH   ] 	base::LaunchUnitTests [0x00CB51B1+109]
[  DEATH   ] 	main [0x005AC1AF+219]
[  DEATH   ] 	__scrt_common_main_seh [0x013769FB+249] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253)
[  DEATH   ] 	BaseThreadInitThunk [0x7699336A+18]
[  DEATH   ] 	RtlInitializeExceptionChain [0x774B9882+99]
[  DEATH   ] 	RtlInitializeExceptionChain [0x774B9855+54]
[  DEATH   ]
[  FAILED  ] PaintControllerUnderInvalidationTest.MoreDrawingInSubsequence (100 ms)