Done in r284514.

This may actually slow things down in some rare cases when we have unbalanced mallocs but still not leaks. 
I can lave with that and I'd actually like to see those and fix. 

Thanks Kostya, rolling libFuzzer for uptaking this in https://codereview.chromium.org/2427033002/

Both clusterfuzz side workaround and libfuzzer fix rolled

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/072eefc45f5b4a1240e38a5af9a7bcd2d6a19ddd

commit 072eefc45f5b4a1240e38a5af9a7bcd2d6a19ddd
Author: inferno <inferno@chromium.org>
Date: Tue Oct 18 23:13:11 2016

[libFuzzer] Roll libFuzzer 3e02228..9aa0bdd

https://chromium.googlesource.com/chromium/llvm-project/llvm/lib/Fuzzer/+log/3e02228..9aa0bdd

BUG=539572, 657088 
TBR=aizatsky@chromium.org, inferno@chromium.org, kcc@chromium.org, ochang@chromium.org

Review-Url: https://codereview.chromium.org/2427033002
Cr-Commit-Position: refs/heads/master@{#426082}

[modify] https://crrev.com/072eefc45f5b4a1240e38a5af9a7bcd2d6a19ddd/DEPS