Roll src/third_party/libprotobuf-mutator/src/ 52af4b0f6..3fc43a01d (8 commits)

https://chromium.googlesource.com/external/github.com/google/libprotobuf-mutator.git/+log/52af4b0f6f55..3fc43a01d721

$ git log 52af4b0f6..3fc43a01d --date=short --no-merges --format='%ad %ae %s'
2017-10-26 vitalybuka Update with UTF-8 details
2017-10-16 vitalybuka Return LIB_PROTO_MUTATOR_FUZZER_LIBRARIES as it's used by OSS-fuzz
2017-10-16 vitalybuka Remove reference to LIB_PROTO_MUTATOR_FUZZER_LIBRARIES and set -fsanitize-coverage=0
2017-10-16 vitalybuka Switch to clang 6.0
2017-10-16 vitalybuka Switch to -fsanitize=fuzzer
2017-09-28 vitalybuka Improve protection against stack overflow
2017-09-13 vitalybuka Fix endif() in cmake file
2017-09-13 vitalybuka Update CMakeLists.txt

Created with:
  roll-dep src/third_party/libprotobuf-mutator/src

Bug: 780535
Change-Id: I0306a463efa4527eb40a45e9faf3269cc8fe1d19
Reviewed-on: https://chromium-review.googlesource.com/749106
Commit-Queue: Jonathan Metzman <metzman@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513213}

DEPS

@@ -127,7 +127,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libprotobuf-mutator
   # and whatever else without interference from each other.
-  'libprotobuf-mutator': '52af4b0f6f55f9d8836acb605e902db49eb8e6b4',
+  'libprotobuf-mutator': '3fc43a01d721ef1bacfefed170bc22abf1b8b051',
 }
 
 # Only these hosts are allowed for dependencies in this DEPS file.