Predator could not provide any possible suspects.

From the below CL observing some changes related to file 'skia_image_filter_proto_converter.cc', hence suspecting the same

https://chromium.googlesource.com/chromium/src/+log/895678e6b233734f4a45a13e9ef9a4049007e514..a1df8ee7f1f3b13134e056ff1f4580ea2aa295ea?pretty=fuller&n=10000

Suspect CL: https://chromium.googlesource.com/chromium/src/+/868f1e2490e14673494aa5a3a82c591fcf50a0a5

metzman@ -- Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f2267d0d1c488cc65e6ea5d5221559044910301e

commit f2267d0d1c488cc65e6ea5d5221559044910301e
Author: Jonathan Metzman <metzman@chromium.org>
Date: Fri Feb 02 20:42:42 2018

[LPM] Speculative fix for Mac builds of skia proto fuzzer.

On Mac builds, it looks like calling WriteNum on a size_t was causing
the compiler to select the templated version of WriteNum rather than the
uint64_t version. Hopefully it won't do the opposite (and break on calls
to WriteNum(uint64_t) because of this fix.

Bug:  808155 , 769578
Change-Id: I8babcf6da5090b9bffdbcc98b573c11c02f2e489
Reviewed-on: https://chromium-review.googlesource.com/899906
Commit-Queue: Jonathan Metzman <metzman@chromium.org>
Reviewed-by: Martin Barbella <mbarbella@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534143}
[modify] https://crrev.com/f2267d0d1c488cc65e6ea5d5221559044910301e/testing/libfuzzer/proto/skia_image_filter_proto_converter.cc
[modify] https://crrev.com/f2267d0d1c488cc65e6ea5d5221559044910301e/testing/libfuzzer/proto/skia_image_filter_proto_converter.h

ClusterFuzz has detected this issue as fixed in range 534019:534158.

Detailed report: https://clusterfuzz.com/testcase?key=4878362099843072

Fuzzer: libFuzzer_skia_image_filter_proto_fuzzer
Job Type: mac_libfuzzer_chrome_asan
Platform Id: mac

Crash Type: CHECK failure
Crash Address: 
Crash State:
  sizeof(T) <= static_cast<size_t>(4) in skia_image_filter_proto_converter.cc
  void skia_image_filter_proto_converter::Converter::WriteNum<unsigned long>
  skia_image_filter_proto_converter::Converter::WriteString
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=mac_libfuzzer_chrome_asan&range=533258:533361
Fixed: https://clusterfuzz.com/revisions?job=mac_libfuzzer_chrome_asan&range=534019:534158

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4878362099843072

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.

ClusterFuzz testcase 4878362099843072 is verified as fixed, so closing issue as verified.

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