GitLab

This will allow us to see how many page loads are affected by the Symantec
distrust
(https://security.googleblog.com/2018/03/distrust-of-symantec-pki-immediate.html).

Note that this doesn't cover iframe main resources that fail to load because
they are distrusted.

Bug: 820582
Change-Id: I4a382dc155f0500222d91c7cdd1eb1a15eea32a6
Reviewed-on: https://chromium-review.googlesource.com/957548
Commit-Queue: Emily Stark <estark@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542365}