Through code search on file StyleEngine.cpp, suspected CL is 
https://chromium.googlesource.com/chromium/src/+/2b9e4d03756be0ca4867bc1a03f8bd69f3eed43b
rune@, could you please take a look?
Thank you

ClusterFuzz has detected this issue as fixed in range 458081:458090.

Detailed report: https://clusterfuzz.com/testcase?key=6278858069508096

Fuzzer: ochang_domfuzzer
Job Type: linux_tsan_chrome_mp
Platform Id: linux

Crash Type: Data race WRITE 4
Crash Address: 0x7f7dcbbbfb78
Crash State:
  blink::Node::setNeedsStyleInvalidation
  blink::StyleInvalidator::scheduleInvalidationSetsForNode
  blink::StyleEngine::attributeChangedForElement
  
Sanitizer: thread (TSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_tsan_chrome_mp&range=456256:456287
Fixed: https://clusterfuzz.com/revisions?job=linux_tsan_chrome_mp&range=458081:458090

Reproducer Testcase: https://clusterfuzz.com/download/AMIfv95KLjaI_WRTQ_pqckU-oTDoA8u_rjuNh_XMKnqcDGWXIuwSaeOCKCUhojz7FefudmtAZnIi9B7C1AeXieJM2-KzgOy6lx8mfoO8-acYB0UlfMgEhY8QdPuvwYzA0bJ9ietAM1WVNjNM4mimvAca38qS2E35ulx3QNwFsdvpYJlwMBDj8tYoJSxTUtKgaWBLYSBedxbPeBrrGkne81qiQEniCMNRpTIknAURFzcuiw2x5wZK8ibbAqsdQZbj3dpDKilRf9bnOOn5jhPAQ3epucPdA_IQCoaH8pBDGMOCfkLvqzwroQxkji1czY13ZFlyfLVbxc9MqaH-EuwMpjHDEM617yYh8_n3ZdleuEHtVHr7Pt35sWO_yB3g-nFQWvD9BZ9FSlrWVd-lI47EwDR0_7G7OpPDDg?testcase_id=6278858069508096


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs 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 6278858069508096 is verified as fixed, so closing issue.

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

Probably introduced by:

https://chromium.googlesource.com/chromium/src/+/3b4b07ced6315a25960ca5a51dd1b7ba88de53db

which got reverted in the fixed range.