Predator and CL did not provide any possible suspects.
Using Code Search for the file, "PaintLayerPainter.cpp" assigning to the concern owner who might be related.

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

So far I cannot reproduce this issue...

ClusterFuzz has detected this issue as fixed in range 492069:492135.

Detailed report: https://clusterfuzz.com/testcase?key=6440119694524416

Fuzzer: inferno_twister
Job Type: mac_asan_content_shell
Platform Id: mac

Crash Type: Null-dereference READ
Crash Address: 0x000000000000
Crash State:
  blink::PaintLayerPainter::PaintLayerWithTransform
  blink::PaintLayerPainter::Paint
  blink::PaintLayerPainter::PaintChildren
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=mac_asan_content_shell&range=490043:490173
Fixed: https://clusterfuzz.com/revisions?job=mac_asan_content_shell&range=492069:492135

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6440119694524416


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 6440119694524416 is verified as fixed, so closing issue as verified.

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