Using the per-revision bisect providing the bisect results,
Good Build: 58.0.3004.3 (revision : 448183)
Bad Build: 58.0.3005.2 (revision : 448507)

You are probably looking for a change made after 448455 (known good), but no later than 448456 (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/efb5b2d95f612ff05ead8077985b77d30fa8edba..fe93dfadae6424df9875c7e9f72b27985ba7d6d1

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

@einbinder- 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/2678183002

Note : Adding RB-Stable as this is a recent regression, please feel to edit/remove this.

Thanks!

einbinder@: Could you please take a look at this.

Note: Issue is still reproducible on the latest canary(58.0.3012.0) of Windows10.

Friendly ping!!

Still we are able to reproduce the issue on latest Canary#58.0.3017.0 of Windows-7.
einbinder@:could you please look into this issue.

Thank you.

Friendly ping!!
Still able to reproduce the issue on latest Canary#58.0.3024.0 of Windows-7.
einbinder@ since this marked as ReleaseBlock-Stable, could you please provide an update on this issue.

Thank You...

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bd3f676ad85ff5e61204c2e8c41d3328fe2ae182

commit bd3f676ad85ff5e61204c2e8c41d3328fe2ae182
Author: einbinder <einbinder@chromium.org>
Date: Wed Mar 01 03:17:55 2017

DevTools: Fix empty TextPrompt with placeholder having two lines

BUG= 689862 

Review-Url: https://codereview.chromium.org/2709613014
Cr-Commit-Position: refs/heads/master@{#453817}

[modify] https://crrev.com/bd3f676ad85ff5e61204c2e8c41d3328fe2ae182/third_party/WebKit/Source/devtools/front_end/ui/textPrompt.css

Tested the issue on windows 7, Mac 10.12.3, Linux Ubuntu 14.04 using chrome version#58.0.3029.0 & latest Canary#59.0.3030.0 with the steps mentioned in comment #0.Observed that unwanted extra space is not seen in text box after clicking on .cls in dev tools as per the intended behaviour. Hence adding TE-Verified labels.
Please find the attached screen cast of the latest Canary version(M59)for the same.
Thanks!!

Deleted: 689862.mp4 1.7 MB

	689862.mp4 1.7 MB View Download

einbinder@: Could you please close the issue if there is no further work to be done here.

[Auto-generated comment by a script] We noticed that this issue is targeted for M-58; it appears the fix may have landed after branch point, meaning a merge might be required. Please confirm if a merge is required here - if so add Merge-Request-58 label, otherwise remove Merge-TBD label. Thanks.

M58 (3029) was branched at Chromium revision 454471. So cl listed #5 is already in M58 branch. No merge is needed here.