Predator and CL did not provide any possible suspects.
Using Code Search for the file, "HTMLFrameElementBase.cpp" assigning to the concern owner.
Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/772e2f76cdab92e73a50192f07b2ea7036c06b79

@tkent -- 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 479627:479644.

Detailed report: https://clusterfuzz.com/testcase?key=4632860205252608

Fuzzer: ifratric-browserfuzzer-v3
Job Type: windows_asan_chrome_no_sandbox
Platform Id: windows

Crash Type: Null-dereference READ
Crash Address: 0x00000000
Crash State:
  blink::HTMLFrameElementBase::DidNotifySubtreeInsertionsToDocument
  blink::ContainerNode::NotifyNodeInserted
  blink::ContainerNode::ParserAppendChild
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=windows_asan_chrome_no_sandbox&range=307759:307774
Fixed: https://clusterfuzz.com/revisions?job=windows_asan_chrome_no_sandbox&range=479627:479644

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4632860205252608


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 4632860205252608 is verified as fixed, so closing issue.

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