The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/aaea8461122ae3c1725ba2c1a4875bd5d65787be

commit aaea8461122ae3c1725ba2c1a4875bd5d65787be
Author: Emily Stark <estark@google.com>
Date: Thu Jun 21 16:04:00 2018

Add UseCounters for Symantec certs to be distrusted in M70

The old Symantec PKI will be fully distrusted in M70
(https://security.googleblog.com/2018/03/distrust-of-symantec-pki-immediate.html). We
already have DevTools console messages in place for affected resources, and this
CL adds UseCounters so that we know how many page loads will be affected.

The counters give us:
- % of page visits with an affected main frame main resource
- % of page visits with an afected subframe main resource
- % of page visits with an affected subresource

Note that these buckets can overlap, for example a single page visit can
increment all 3 counters.

Bug:  853868 
Change-Id: I7ae103efcc47a3e4e381b35c6803ef2d8ed4c7fb
Reviewed-on: https://chromium-review.googlesource.com/1107841
Commit-Queue: Emily Stark <estark@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569282}
[modify] https://crrev.com/aaea8461122ae3c1725ba2c1a4875bd5d65787be/third_party/blink/public/platform/web_feature.mojom
[modify] https://crrev.com/aaea8461122ae3c1725ba2c1a4875bd5d65787be/third_party/blink/renderer/core/loader/document_loader.cc
[modify] https://crrev.com/aaea8461122ae3c1725ba2c1a4875bd5d65787be/third_party/blink/renderer/core/loader/frame_fetch_context.cc
[modify] https://crrev.com/aaea8461122ae3c1725ba2c1a4875bd5d65787be/tools/metrics/histograms/enums.xml

Requesting a merge for M68. This is a small metrics change that is needed to plan for a large disruptive change coming in M70. I've verified the change on canary.

This bug requires manual review: M68 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), kariahda@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Approving merge to M68. Branch:3440

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/30210fac052c277dacddf145372e15983415a8f2

commit 30210fac052c277dacddf145372e15983415a8f2
Author: Christopher Thompson <cthomp@chromium.org>
Date: Tue Jun 26 23:08:55 2018

Add UseCounters for Symantec certs to be distrusted in M70

[Merge to M68 Beta]

The old Symantec PKI will be fully distrusted in M70
(https://security.googleblog.com/2018/03/distrust-of-symantec-pki-immediate.html). We
already have DevTools console messages in place for affected resources, and this
CL adds UseCounters so that we know how many page loads will be affected.

The counters give us:
- % of page visits with an affected main frame main resource
- % of page visits with an afected subframe main resource
- % of page visits with an affected subresource

Note that these buckets can overlap, for example a single page visit can
increment all 3 counters.

TBR=estark@google.com

(cherry picked from commit aaea8461122ae3c1725ba2c1a4875bd5d65787be)

Bug:  853868 
Change-Id: I7ae103efcc47a3e4e381b35c6803ef2d8ed4c7fb
Reviewed-on: https://chromium-review.googlesource.com/1107841
Commit-Queue: Emily Stark <estark@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#569282}
Reviewed-on: https://chromium-review.googlesource.com/1115898
Reviewed-by: Christopher Thompson <cthomp@chromium.org>
Cr-Commit-Position: refs/branch-heads/3440@{#542}
Cr-Branched-From: 010ddcfda246975d194964ccf20038ebbdec6084-refs/heads/master@{#561733}
[modify] https://crrev.com/30210fac052c277dacddf145372e15983415a8f2/third_party/blink/public/platform/web_feature.mojom
[modify] https://crrev.com/30210fac052c277dacddf145372e15983415a8f2/third_party/blink/renderer/core/loader/document_loader.cc
[modify] https://crrev.com/30210fac052c277dacddf145372e15983415a8f2/third_party/blink/renderer/core/loader/frame_fetch_context.cc
[modify] https://crrev.com/30210fac052c277dacddf145372e15983415a8f2/tools/metrics/histograms/enums.xml