As per the  Issue 754500  owner assigning this issue to @wolenetz.
@wolenetz -- Could you please look into this issue, kindly reassign if it has nothing to do with your changes.
Thanks.

Looks quite similar in debug logs to  bug 766472 .

CL: https://chromium-review.googlesource.com/c/chromium/src/+/677774

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/194995c434ed179b0b2cba1269a2f4fd1d4dbcae

commit 194995c434ed179b0b2cba1269a2f4fd1d4dbcae
Author: Matt Wolenetz <wolenetz@chromium.org>
Date: Thu Sep 21 23:13:44 2017

MSE+SRC=: Let early PITB::FailTest() during PITB::Start*() stop the Start*()

Modifies PITB::StartPipelineWithMediaSource() to let any PITB::OnEnded()
or PITB()::OnError() stop the run loop and let the method return. In
cases where OnError (like that triggered if EME is indicated in init
segment -> PITB::FailTest()) or OnEnded occur prior to pipeline
completing start-up, this avoids one kind of fuzzer timeout.

Also includes addition of PITB helpers to assist common "RunUntilIdle"
scenarios and refactoring of PITB to use those helpers.

Also changes the SRC= PITB::StartInternal() to similarly allow early
fuzzer EME callback to quit the run-loop early, possibly mitigating any
similar timeouts in SRC= media_pipeline_integration_fuzzer.

BUG= 766472 , 766669 

Change-Id: I8307db26828eaf04ae92dc1dbee4fa6969c5dd37
Reviewed-on: https://chromium-review.googlesource.com/677774
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Commit-Queue: Matthew Wolenetz <wolenetz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503605}
[modify] https://crrev.com/194995c434ed179b0b2cba1269a2f4fd1d4dbcae/media/test/pipeline_integration_test_base.cc
[modify] https://crrev.com/194995c434ed179b0b2cba1269a2f4fd1d4dbcae/media/test/pipeline_integration_test_base.h

#6 should fix this. Pending CF verification...

ClusterFuzz has detected this issue as fixed in range 503598:503620.

Detailed report: https://clusterfuzz.com/testcase?key=4791639502749696

Fuzzer: libFuzzer_mediasource_MP4_AACLC_AVC_pipeline_integration_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: Timeout (exceeds 25 secs)
Crash Address: 
Crash State:
  mediasource_MP4_AACLC_AVC_pipeline_integration_fuzzer
  
Sanitizer: address (ASAN)

Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_asan&range=503598:503620

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4791639502749696

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reference.md for more information.

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