Predator and CL did not provide any possible suspects.
Using Code Search for the file, "splitting_filter.c" assigning to the concern using Git Blame.

Suspecting Commit#
https://chromium.googlesource.com/external/webrtc/trunk/webrtc.git/+/c49ec1327c1d956c6c889cf1f32a7f9920d76149

@pbos -- Could you please look into the issue, kindly re-assign if this is not related to your changes.
Thank You.

Henrik can you reassign? This is old code, my blame is based on s/foo/bar/g changes.

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/16005b77839e8d2af95405e6434a7fbdbf4b5851

commit 16005b77839e8d2af95405e6434a7fbdbf4b5851
Author: Alex Loiko <aleloi@webrtc.org>
Date: Tue Jul 18 10:02:28 2017

Remove potential left shift of negative value in WebRtcSpl_AnalysisQMF

WebRtcSpl_AnalysisQMF takes raw (user) audio input represented by
int16_t samples. The samples are converted to Q10 with the
WEBRTC_SPL_LSHIFT_W32 macro. The macro is implemeted as a left
shift. This CL replaces the shift with a multiplication, similar
to https://codereview.webrtc.org/2253943002

TBR=kwiberg@webrtc.org

Bug:  chromium:735773 
Change-Id: Ic4e63269390e82b86f304e5aa1b5e2dc22122bcb
Reviewed-on: https://chromium-review.googlesource.com/552124
Commit-Queue: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19068}
[modify] https://crrev.com/16005b77839e8d2af95405e6434a7fbdbf4b5851/webrtc/common_audio/signal_processing/splitting_filter.c

ClusterFuzz has detected this issue as fixed in range 488172:488220.

Detailed report: https://clusterfuzz.com/testcase?key=6560249292259328

Fuzzer: libFuzzer_audio_processing_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Undefined-shift
Crash Address: 
Crash State:
  WebRtcSpl_AnalysisQMF
  webrtc::SplittingFilter::TwoBandsAnalysis
  webrtc::AudioProcessingImpl::ProcessCaptureStreamLocked
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=481133:481204
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=488172:488220

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6560249292259328


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.