Roll src/third_party/boringssl/src 5267ef7b4..6ff2ba80b

https://boringssl.googlesource.com/boringssl/+log/5267ef7b4aa6385c0351ae10ce3092828cca4909..6ff2ba80b758025fdb137d9357dcbba0a9c04dbf

BUG=none

Change-Id: I0ed82f0919a02f8e8f57f67ff4fbdef8ea74f998
Reviewed-on: https://chromium-review.googlesource.com/1099422Reviewed-by: David Benjamin <davidben@chromium.org>
Commit-Queue: David Benjamin <davidben@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567023}

DEPS

@@ -137,7 +137,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.
-  'boringssl_revision': '5267ef7b4aa6385c0351ae10ce3092828cca4909',
+  'boringssl_revision': '6ff2ba80b758025fdb137d9357dcbba0a9c04dbf',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling google-toolbox-for-mac
   # and whatever else without interference from each other.