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

Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/bfb95378b11f6e06cb99fb001efcd8d8f57d346a

@wangxianzhu -- Could you please look into the issue, kindly re-assign if this is not related to your changes.
Thank You.

ClusterFuzz has detected this issue as fixed in range 494105:494259.

Detailed report: https://clusterfuzz.com/testcase?key=5112446519083008

Fuzzer: inferno_layout_test_fuzzer
Job Type: linux_ubsan_vptr_content_shell_drt
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  false in PaintController.cpp
  blink::PaintController::CheckUnderInvalidation
  blink::PaintController::ProcessNewItem
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_content_shell_drt&range=455091:455392
Fixed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_content_shell_drt&range=494105:494259

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5112446519083008

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.

ClusterFuzz testcase 5112446519083008 is verified as fixed, so closing issue as verified.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.