Predator and CL could not provide any possible suspects.
Using Code Search for the file, "scoped_task_environment.cc" assigning to concern owner from GIT Blame.

Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/b199f1bef099a0b34576f10fd57e713551e39349

@fdoray -- 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 493044:493126.

Detailed report: https://clusterfuzz.com/testcase?key=4967795644432384

Fuzzer: libFuzzer_media_pipeline_integration_fuzzer
Job Type: libfuzzer_chrome_msan
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  !queue_empty_closure_ in scoped_task_environment.cc
  SignalHandler
  base::test::ScopedTaskEnvironment::TestTaskTracker::AssertOnQueueEmptyClosureIsN
  
Sanitizer: memory (MSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_msan&range=490796:490827
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_msan&range=493044:493126

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4967795644432384

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md 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 4967795644432384 is verified as fixed, so closing issue as verified.

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