Using the per-revision bisect providing the bisect results,
Good build:55.0.2851.0(Revision:416559).
Bad build: 55.0.2853.0 (Revision:416812).

You are probably looking for a change made after 416699 (known good), but no later than 416700 (first known bad).

CHANGELOG URL:

The script might not always return single CL as suspect as some perf builds might get missing due to failure. 
  https://chromium.googlesource.com/chromium/src/+log/59086df0374a53915887b36d081fef7f84cead72..8b3813b7f3ac9e197305cc440b78c81773cd07af

From the CL above, assigning the issue to the concern owner 

@jam - Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Review-Url: https://codereview.chromium.org/2296953004

Thanks !

Adding release block label, please undo if not the case.

+estark FYI

hmm, this code hasn't changed since well before branchpoint, and on trunk this works fine.

Can you post a link to a build where I can try this? Is this happening on beta or canary, m55 or m56?

@jam:

This is working fine on M54 market beta - 54.02840.59

Issue is broken in M55 and also able to reproduce it on M56 Canary build 56.0.2895.0, Just tried on a MAC M55 dev build and was able to reproduce it:

Build URL:
===========
https://pantheon.corp.google.com/storage/browser/chrome-signed/desktop-5c0tCh/55.0.2883.21/mac64/?pli=1

Thanks.!

jam@, could you please take a look and fix this asap as this is marked as M55 stable blocker.

I had a tough time repro'ing this and tried branches, because I was only testing the docked out view. Turns out this only fails if the devtools window is docked.

Fix should be easy, I'll send one out.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2697c72ef37e963d6cb465780683901833f59a6a

commit 2697c72ef37e963d6cb465780683901833f59a6a
Author: jam <jam@chromium.org>
Date: Fri Oct 21 22:33:02 2016

Fix certificate viewer not showing up for subresources if the devtools window is docked.

BUG= 657270 

Review-Url: https://chromiumcodereview.appspot.com/2427323005
Cr-Commit-Position: refs/heads/master@{#426917}

[modify] https://crrev.com/2697c72ef37e963d6cb465780683901833f59a6a/chrome/browser/devtools/devtools_window.cc
[modify] https://crrev.com/2697c72ef37e963d6cb465780683901833f59a6a/chrome/browser/devtools/devtools_window.h

Verified this issue on Ubuntu 14.04, Windows-10 and Mac 10.12 using chrome latest Dev M56-56.0.2899.0 by following steps mentioned in the original comment. Observed the certificate is able top open as expected with no issues. Hence adding TE-Verified label.

We will be verifying this issue again on chrome once the merge is landed to M55 latest build.

Thanks!

Deleted: 657270.ogv 2.1 MB

	657270.ogv 2.1 MB View Download

Your change meets the bar and is auto-approved for M55 (branch: 2883)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/43872838e229de38cd0e9b32f80f810f78b14b0e

commit 43872838e229de38cd0e9b32f80f810f78b14b0e
Author: John Abd-El-Malek <jam@chromium.org>
Date: Mon Oct 24 19:47:25 2016

Fix certificate viewer not showing up for subresources if the devtools window is docked.

BUG= 657270 

Review-Url: https://chromiumcodereview.appspot.com/2427323005
Cr-Commit-Position: refs/heads/master@{#426917}
(cherry picked from commit 2697c72ef37e963d6cb465780683901833f59a6a)

Review URL: https://codereview.chromium.org/2450513002 .

Cr-Commit-Position: refs/branch-heads/2883@{#251}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/43872838e229de38cd0e9b32f80f810f78b14b0e/chrome/browser/devtools/devtools_window.cc
[modify] https://crrev.com/43872838e229de38cd0e9b32f80f810f78b14b0e/chrome/browser/devtools/devtools_window.h

Verified the issue on Windows-10, Ubuntu 14.04 and Mac OS 10.12 using chrome latest Beta M55-55.0.2883.28 by following steps mentioned in the original comment. Observed the certificate window opens as expected. Hence adding TE-Verified label.

Deleted: Screen Shot 2016-10-26 at 11.05.58 AM.png 253 KB

	Screen Shot 2016-10-26 at 11.05.58 AM.png 253 KB View Download

**** Bulk edit -  please ignore if not applicable ****

A friendly reminder that M55 Stable is launch is coming soon! Your bug is labelled as Stable ReleaseBlock, pls make sure to land the fix and get it merged into the release branch ASAP so it gets enough baking time in Beta (before Stable promotion). Thank you!

Jam@, Can this issue mark as fixed?
Thank you.

Thank you very much.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/43872838e229de38cd0e9b32f80f810f78b14b0e

commit 43872838e229de38cd0e9b32f80f810f78b14b0e
Author: John Abd-El-Malek <jam@chromium.org>
Date: Mon Oct 24 19:47:25 2016

Fix certificate viewer not showing up for subresources if the devtools window is docked.

BUG= 657270 

Review-Url: https://chromiumcodereview.appspot.com/2427323005
Cr-Commit-Position: refs/heads/master@{#426917}
(cherry picked from commit 2697c72ef37e963d6cb465780683901833f59a6a)

Review URL: https://codereview.chromium.org/2450513002 .

Cr-Commit-Position: refs/branch-heads/2883@{#251}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/43872838e229de38cd0e9b32f80f810f78b14b0e/chrome/browser/devtools/devtools_window.cc
[modify] https://crrev.com/43872838e229de38cd0e9b32f80f810f78b14b0e/chrome/browser/devtools/devtools_window.h

[Automated comment] removing mislabelled merge-merged-2840

[Automated comment] removing mislabelled merge-merged-2840