Able to reproduce this issue on reported version 65.0.3325.162, on latest stable 65.0.3325.181 and on latest beta 66.0.3359.45 using Windows 10, Mac 10.13.3 and Ubuntu 14.04. But issue is not seen on latest canary 67.0.3377.0. Hence providing reverse bisect info.

Last Bad Build: 67.0.3362.0
First Good Build: 67.0.3364.0

You are probably looking for a change made after 541172 (known good), but no later than 541173 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/ab5c06e68fe24e55572a69374b36b1d7fd83c4c5..71f7b2b768f7edafdd46553e0c42376ddc96f117

Probably fixed by https://chromium-review.googlesource.com/949046

@ mkwst: Please confirm the bug and help in re-assigning to appropriate owner if it is not related to your change. Please merge the fix to M-65 and M-66 if it is safe. Adding RB-Stable for M-65. Please remove if not the case.

Thanks!

Requesting merge of https://chromium-review.googlesource.com/949046 to 66. I don't think it's worth merging to 65.

This bug requires manual review: M66 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), cmasso@(iOS), josafat@(ChromeOS), abdulsyed@(Desktop)

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

Thank you mkwst@. We won't consider this as a blocker for M65 further rollout based on comment #3.

Can we target this for M67? 

I'd suggest that the patch is safe enough to target 66. It's tiny (three lines modified, three removed, plus test modifications) It's been in for two-and-a-half weeks, and this is the third or fourth report I've seen. Given the prevalence of YouTube embeds, I'd like to get the message off folks' consoles to stop worrying developers.

Approving merge to M66. Branch:3359

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a6c614be7313e8428f01f08d05a7ef3f59992c95

commit a6c614be7313e8428f01f08d05a7ef3f59992c95
Author: Mike West <mkwst@chromium.org>
Date: Mon Mar 26 08:17:48 2018

Restore cross-origin reporting to the XSS Auditor.

TBR=mkwst@chromium.org

(cherry picked from commit 71f7b2b768f7edafdd46553e0c42376ddc96f117)

Bug:  811440 ,  823624 
Change-Id: I51253d721b30255f8270eacb67d5bcf629f90da1
Reviewed-on: https://chromium-review.googlesource.com/949046
Commit-Queue: Mike West <mkwst@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#541173}
Reviewed-on: https://chromium-review.googlesource.com/979654
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/branch-heads/3359@{#422}
Cr-Branched-From: 66afc5e5d10127546cc4b98b9117aff588b5e66b-refs/heads/master@{#540276}
[modify] https://crrev.com/a6c614be7313e8428f01f08d05a7ef3f59992c95/third_party/WebKit/LayoutTests/http/tests/security/xssAuditor/report-script-tag-cross-origin-expected.txt
[modify] https://crrev.com/a6c614be7313e8428f01f08d05a7ef3f59992c95/third_party/WebKit/LayoutTests/http/tests/security/xssAuditor/report-script-tag-cross-origin-https-expected.txt
[modify] https://crrev.com/a6c614be7313e8428f01f08d05a7ef3f59992c95/third_party/WebKit/LayoutTests/http/tests/security/xssAuditor/report-script-tag-cross-origin-https.html
[modify] https://crrev.com/a6c614be7313e8428f01f08d05a7ef3f59992c95/third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp

Thank you.

Merged to 66 in https://chromium-review.googlesource.com/c/chromium/src/+/979654. Closing this out.