The CL for this is out here: https://chromium-review.googlesource.com/c/chromium/src/+/751288/3

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/425d4cd82b3cdee276acf851d46d3eaf7662946a

commit 425d4cd82b3cdee276acf851d46d3eaf7662946a
Author: Chris Blume <cblume@google.com>
Date: Fri Nov 03 21:34:03 2017

Add fuzzer for zlib's deflateSetDictionary

We want to cover all of zlib's external APIs.
deflateSetDictionary() currently isn't covered.

BUG=780926

Change-Id: Ie2da648a4d58fca0745c814b004d3859e81a85a6
Reviewed-on: https://chromium-review.googlesource.com/752070
Reviewed-by: Max Moroz <mmoroz@chromium.org>
Reviewed-by: Adenilson Cavalcanti <cavalcantii@chromium.org>
Commit-Queue: Chris Blume <cblume@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513917}
[modify] https://crrev.com/425d4cd82b3cdee276acf851d46d3eaf7662946a/third_party/zlib/BUILD.gn
[add] https://crrev.com/425d4cd82b3cdee276acf851d46d3eaf7662946a/third_party/zlib/contrib/tests/fuzzers/deflate_set_dictionary_fuzzer.cc