Predator and CL did not provide any possible suspects.
Using Code Search for the file, "vector.h" assigning to concern owner.

Suspecting Commit#
https://chromium.googlesource.com/v8/v8.git/+/74543fedd8dcef8c5963c5779010e73358467eed

@mtrofin -- Could you please look into the issue, please re-assign if it has nothing to do with your changes.
Thank You.

This is unrelated - the CHECK observes that an invalid index is provided by the caller.

The only thing I could do at this point is bisect. Is that something I could get help with?

Thanks!

Also, this is third_party\WebKit\Source\platform\wtf\Vector.h, not v8/src/vector.h

It appears (bisecting) that 24e763b891b69163e01e96f6ca45e173c7101369 is the culprit.

This does not appear related to my changes. All that patch does is move a bunch of Python scripts around.

Redirecting to the layout team for further action.

Strange, I can't reproduce this against a normal build at commit position 492393 - normally this kind of failure doesn't require a full asan build.

Can anyone else reproduce it?

Mmm, can't reproduce on an asan build at 492393 either.

ClusterFuzz has detected this issue as fixed in range 495542:495750.

Detailed report: https://clusterfuzz.com/testcase?key=4770349421166592

Fuzzer: inferno_layout_test_unmodified
Job Type: windows_asan_chrome_no_sandbox
Platform Id: windows

Crash Type: CHECK failure
Crash Address: 
Crash State:
  i < size() in Vector.h
  blink::LayoutBlockFlow::AppendFloatsToLastLine
  blink::LayoutBlockFlow::LayoutRunsAndFloatsInRange
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=windows_asan_chrome_no_sandbox&range=489314:489347
Fixed: https://clusterfuzz.com/revisions?job=windows_asan_chrome_no_sandbox&range=495542:495750

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4770349421166592

See https://github.com/google/clusterfuzz-tools for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.