Predator and CL could not provide any possible suspects.
Using the code search for the file, “Renderer.cpp” assigning to concern owner from GIT revision log.
Suspecting Commit#
https://swiftshader.googlesource.com/SwiftShader.git/+/bc6ce4f1f78fb714f59caecf9ed0c886b99f1c82

@sugoi -- Could you please look into this issue, kindly reassign if it has nothing to do with your changes.
Thank You.

The following revision refers to this bug:
  https://swiftshader.googlesource.com/SwiftShader.git/+/f2520e1905f76f3397720ceef2a4dd60b0f2ec70

commit f2520e1905f76f3397720ceef2a4dd60b0f2ec70
Author: Alexis Hetu <sugoi@google.com>
Date: Thu Oct 26 19:00:42 2017

Data race fix

There's a data race involving threadCount,
so it is now an AtomicInt object.

Also removed unused extern variables.

 Bug chromium:778254   chromium:776621 

Change-Id: I93174e8f4e5e48f26414ba9c81bb9a2c317dbf73
Reviewed-on: https://swiftshader-review.googlesource.com/13290
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>

[modify] https://crrev.com/f2520e1905f76f3397720ceef2a4dd60b0f2ec70/src/Renderer/Renderer.cpp
[modify] https://crrev.com/f2520e1905f76f3397720ceef2a4dd60b0f2ec70/src/Renderer/Renderer.hpp

ClusterFuzz has detected this issue as fixed in range 511801:511810.

Detailed report: https://clusterfuzz.com/testcase?key=5997389310853120

Fuzzer: attekett_dom_fuzzer
Job Type: linux_tsan_chrome_mp
Platform Id: linux

Crash Type: Data race WRITE 4
Crash Address: 0x7fb1ef3e5050
Crash State:
  sw::Renderer::updateConfiguration
  sw::Renderer::Renderer
  es2::Device::Device
  
Sanitizer: thread (TSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_tsan_chrome_mp&range=479114:479249
Fixed: https://clusterfuzz.com/revisions?job=linux_tsan_chrome_mp&range=511801:511810

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5997389310853120

See https://github.com/google/clusterfuzz-tools 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 5997389310853120 is verified as fixed, so closing issue as verified.

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7e813690449fb7265efb50b410dc271e5f63cf05

commit 7e813690449fb7265efb50b410dc271e5f63cf05
Author: Alexis Hetu <sugoi@google.com>
Date: Fri Oct 27 19:22:05 2017

Roll SwiftShader ec5da19..6e27fea

https://swiftshader.googlesource.com/SwiftShader.git/+log/ec5da19..6e27fea

BUG= chromium:778254   chromium:776621   chromium:775957 

TBR=kbr@chromium.org

TEST=bots

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel,linux_chromium_cfi_rel_ng;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Change-Id: I77c9aa6852f23337dc3358ece917299a6e3f1db3
Reviewed-on: https://chromium-review.googlesource.com/741920
Commit-Queue: Alexis Hétu <sugoi@chromium.org>
Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512264}
[modify] https://crrev.com/7e813690449fb7265efb50b410dc271e5f63cf05/DEPS