Predator and CL could not provide any possible suspects.

Using Code Search for the file, "document.cc" suspecting the below Cl might have caused this issue

Suspect CL: https://chromium.googlesource.com/chromium/src/+/fe7f8c3cc9889e4a1fd18742691d621982b2c171

schenney@ -- Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thanks!

Duplicate of  bug 890585 ?

Yes.

ClusterFuzz has detected this issue as fixed in range 624368:624374.

Detailed report: https://clusterfuzz.com/testcase?key=6239326311284736

Fuzzer: mbarbella_js_mutation_layout
Job Type: linux_lsan_chrome_mp
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000240
Crash State:
  View
  blink::Document::UpdateStyleAndLayoutIgnorePendingStylesheets
  blink::FrameSelection::ComputeVisibleSelectionInDOMTreeDeprecated
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_lsan_chrome_mp&range=594766:594769
Fixed: https://clusterfuzz.com/revisions?job=linux_lsan_chrome_mp&range=624368:624374

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6239326311284736

See https://github.com/google/clusterfuzz-tools for instructions to reproduce this bug locally.

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