Issue 891900 

Unable to find actual suspect through code search and also observing no CL's under regression range, hence adding appropriate label and requesting someone from Dev team to look in to this issue.

Thanks!

dalecurtis@, can you please look into this change (https://chromium.googlesource.com/chromium/src/+/356d76e89ecc9fa38632aedf2d8b306d35485bb1) if it's related?

Thank you!

=>chcunningham as part of next roll. I'd guess this is the same infinite trun issues as we see elsewhere. It has nothing to do with the CL in c#5 since that's ANdroid only.

This is classic infinite trun generated by zero size; no real check we can do here unfortunately :/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/75cba529525fee4b6b5c7a6b7d5b113ed80dd59d

commit 75cba529525fee4b6b5c7a6b7d5b113ed80dd59d
Author: Dale Curtis <dalecurtis@chromium.org>
Date: Sat Oct 13 01:58:16 2018

Skip noop loop if there is no data to actually read.

The trun element is capable of generating sample information from
zero data, in these cases there's no reason to iterate 0..sample_count.

Hopefully this can help reduce timeouts in the fuzzers too; though now
they'll probably just OOM instead.

BUG= 891900 
TEST=none
R=chcunningham

Change-Id: I9466bbbc1238cba2c5d28f12f5efff506568ac28
Reviewed-on: https://chromium-review.googlesource.com/c/1279360
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599465}
[modify] https://crrev.com/75cba529525fee4b6b5c7a6b7d5b113ed80dd59d/media/formats/mp4/box_definitions.cc

ClusterFuzz has detected this issue as fixed in range 599464:599465.

Detailed report: https://clusterfuzz.com/testcase?key=4845008625336320

Fuzzer: libFuzzer_mediasource_MP4_AVC1_pipeline_integration_fuzzer
Job Type: libfuzzer_chrome_msan
Platform Id: linux

Crash Type: Timeout (exceeds 25 secs)
Crash Address: 
Crash State:
  mediasource_MP4_AVC1_pipeline_integration_fuzzer
  
Sanitizer: memory (MSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_msan&range=509426:509655
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_msan&range=599464:599465

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4845008625336320

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.