The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/90000d23c0d92b9e01726ad9c3233f0d955b0d5b

commit 90000d23c0d92b9e01726ad9c3233f0d955b0d5b
Author: Emily Stark <estark@google.com>
Date: Sat Mar 10 08:19:41 2018

Record UseCounter for distrusted Symantec resources

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}
[modify] https://crrev.com/90000d23c0d92b9e01726ad9c3233f0d955b0d5b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
[modify] https://crrev.com/90000d23c0d92b9e01726ad9c3233f0d955b0d5b/third_party/WebKit/public/platform/web_feature.mojom
[modify] https://crrev.com/90000d23c0d92b9e01726ad9c3233f0d955b0d5b/tools/metrics/histograms/enums.xml

Requesting a merge for #3. It's a small metrics change that will be important for the Symantec deprecation in M66. I've verified the histogram on Canary.

Approving merge to M66 branch 3359 per comment #4 and per offline chat with awhalley@.

Approving for Merge to 66. branch:3359

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/805d40380923d5f9b7976369611e0ef32f1a7ae2

commit 805d40380923d5f9b7976369611e0ef32f1a7ae2
Author: Emily Stark <estark@google.com>
Date: Wed Mar 14 20:07:29 2018

Record UseCounter for distrusted Symantec resources

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.

TBR=estark@google.com

(cherry picked from commit 90000d23c0d92b9e01726ad9c3233f0d955b0d5b)

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-Original-Commit-Position: refs/heads/master@{#542365}
Reviewed-on: https://chromium-review.googlesource.com/963294
Reviewed-by: Emily Stark <estark@chromium.org>
Cr-Commit-Position: refs/branch-heads/3359@{#243}
Cr-Branched-From: 66afc5e5d10127546cc4b98b9117aff588b5e66b-refs/heads/master@{#540276}
[modify] https://crrev.com/805d40380923d5f9b7976369611e0ef32f1a7ae2/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
[modify] https://crrev.com/805d40380923d5f9b7976369611e0ef32f1a7ae2/third_party/WebKit/public/platform/web_feature.mojom
[modify] https://crrev.com/805d40380923d5f9b7976369611e0ef32f1a7ae2/tools/metrics/histograms/enums.xml