On an unrelated bug, I had the failure:

https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8924157816115975376/+/steps/webkit_unit_tests__retry_with_patch_/0/logs/WorkletAnimationTest.CurrentTimeFromDocumentTimelineIsOffsetByStartTime__status_FAILURE_SUCCESS_/0

[ RUN      ] WorkletAnimationTest.CurrentTimeFromDocumentTimelineIsOffsetByStartTime
../../third_party/blink/renderer/modules/animationworklet/worklet_animation_test.cc(130): error: The difference between 123.4 and input->updated_animations[0].current_time is 0.0010000000000047748, which exceeds error, where
123.4 evaluates to 123.40000000000001,
input->updated_animations[0].current_time evaluates to 123.399, and
error evaluates to 0.001.
Stack trace:
Backtrace:
	StackTraceGetter::CurrentStackTrace [0x0282EF48+40]
	testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop [0x0283665B+69]
	testing::internal::AssertHelper::operator= [0x028362C6+48]

[  FAILED  ] WorkletAnimationTest.CurrentTimeFromDocumentTimelineIsOffsetByStartTime (156 ms)

> yigu as they added the test.