What steps will reproduce the problem?
1. Do an official build
2. Run blink_platform_unittests


What is the expected result?

Passes

What happens instead of that?

Fails, e.g. here https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.fyi%2FCrWinClang64_tester%2F5806%2F%2B%2Frecipes%2Fsteps%2Fblink_platform_unittests%2F0%2Flogs%2FPaintControllerUnderInvalidationTest.MoreDrawingInSubsequence%2F0

[ RUN      ] PaintControllerUnderInvalidationTest.MoreDrawingInSubsequence
../../third_party/WebKit/Source/platform/graphics/paint/PaintControllerTest.cpp(2337): error: Death test: TestMoreDrawingInSubsequence()
    Result: died but not with expected error.
  Expected: Check failed: false. Can't find cached display item
Actual msg:
[  DEATH   ] [4240:1684:0411/041228.773:6448394:WARNING:test_suite.cc(236)] Test launcher output path C:\Users\CHROME~2\AppData\Local\Temp\3928_14887\test_results.xml exists. Not adding test launcher result printer.
[  DEATH   ] Backtrace:
[  DEATH   ] 	blink::PaintController::FindOutOfOrderCachedItemForward [0x0000000140144F81+129]
[  DEATH   ] 	blink::PaintController::UseCachedDrawingIfPossible [0x0000000140143E89+137]
[  DEATH   ] 	blink::DrawRect [0x000000013F836D7A+42]
[  DEATH   ] 	blink::PaintControllerUnderInvalidationTest::TestMoreDrawingInSubsequence [0x000000013F8523F1+561]
[  DEATH   ] 	blink::PaintControllerUnderInvalidationTest_MoreDrawingInSubsequence_Test::TestBody [0x000000013F85210C+204]
[  DEATH   ] 	testing::Test::Run [0x0000000140677B77+183]
[  DEATH   ] 	testing::TestInfo::Run [0x00000001406783B3+211]
[  DEATH   ] 	testing::TestCase::Run [0x00000001406787BF+271]
[  DEATH   ] 	testing::internal::UnitTestImpl::RunAllTests [0x000000014067D014+628]
[  DEATH   ] 	testing::UnitTest::Run [0x000000014067CD22+162]
[  DEATH   ] 	base::TestSuite::Run [0x00000001402420C4+132]
[  DEATH   ] 	main [0x000000013F9D54FA+350]
[  DEATH   ] 	base::LaunchUnitTests [0x0000000140242BFD+141]
[  DEATH   ] 	main [0x000000013F9D5498+252]
[  DEATH   ] 	__scrt_common_main_seh [0x0000000140984649+285] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253)
[  DEATH   ] 	BaseThreadInitThunk [0x00000000777959BD+13]
[  DEATH   ] 	RtlUserThreadStart [0x00000000779CA2E1+33]
[  DEATH   ]
[  FAILED  ] PaintControllerUnderInvalidationTest.MoreDrawingInSubsequence (107 ms)



chrishtr, looks like you touched the test recently, so probably yours. It started failing in https://build.chromium.org/p/chromium.fyi/builders/CrWinClang64%20tester/builds/5777 so my money is on https://codereview.chromium.org/2793233002

Since the stack mentions death tests, note that we don't include the text passed to CHECK in official builds, so you can't check for that in official tests. See e.g. my comments at the bottom of https://codereview.chromium.org/2549093009/ for strategies for dealing with this (including "don't use death tests since they're kind of a pain and often not worth the cost", but others too)