Using the per-revision bisect providing the bisect results,
Good build:58.0.3026.0 (Revision:453454).
Bad build:58.0.3027.0 (Revision:453800).

You are probably looking for a change made after 453683 (known good), but no later than 453684 (first known bad).

CHANGE-LOG URL:
---------------
https://chromium.googlesource.com/chromium/src/+log/5165a30947f7e933c1cc3b5d902b7bbae1873976..aa40908dd04900048559b86f7eeae484e6623e11

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

@scottchen : Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.

Review-Url: https://codereview.chromium.org/2715863002
Note :Able to reproduce the issue in Win 10.0,Ubuntu 14.04 & Mac 10.12.3 and Able to reproduce in latest Canary #59.0.3047.0

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/29049fd00eb628cff76d2eda785e4e03e80be962

commit 29049fd00eb628cff76d2eda785e4e03e80be962
Author: scottchen <scottchen@chromium.org>
Date: Wed Mar 22 22:21:50 2017

MD Settings: make input with error msg scale spacing with font-size.

BUG= 703528 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2760393004
Cr-Commit-Position: refs/heads/master@{#458897}

[modify] https://crrev.com/29049fd00eb628cff76d2eda785e4e03e80be962/chrome/browser/resources/settings/search_engines_page/search_engine_dialog.html

Verified on Mac os 10.12.3 , ubuntu 14.04 and windows 7 using chrome M59 #59.0.3053.3 and issue is still reproduced .

Steps tried to reproduce :

1.Launched Chrome and navigated to chrome://settings/appearance, changed Font Size to 'Very Large'.
2.Navigated to chrome://settings/searchEngines and scrolled down, in 'Other Search Engines' clicked on 'ADD'
3.On 'Add Search Engine' overlay for 'Search Engine' pressed 'Space Bar' and observed still space issue .

Attached screenshot for reference.

@scottchen--COuld you please check attached screenshot and steps , and please let us know if we had missed any steps in verifying the issue.

Thanks!

Deleted: 703528.png 186 KB

	703528.png 186 KB View Download

scottchen@, can you please take a look?

Thank you!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bc5ec856b729b019f0933b04baca929dcca60626

commit bc5ec856b729b019f0933b04baca929dcca60626
Author: scottchen <scottchen@chromium.org>
Date: Mon Apr 03 19:28:30 2017

MD Settings: more consistently fix error message space for search engine

I found a really weird behavior -
<paper-input-container> has an "@apply(--paper-input-container)" rule, which generates a "padding: var(--paper-input-container_-_padding, 8px 0)" rule when I set "padding-bottom" in the mixin from my element.

However, about 3 out of 10 times, the renderer doesn't seem to recognize that "padding-bottom" is part of "padding" and behaves like, "well the 'padding' rule isn't specified so I'm gonna render the fallback '8px 0'".

So I explicitly specified a "padding" rule and the intermittent bug went away.

BUG= 703528 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2788803003
Cr-Commit-Position: refs/heads/master@{#461502}

[modify] https://crrev.com/bc5ec856b729b019f0933b04baca929dcca60626/chrome/browser/resources/settings/search_engines_page/search_engine_dialog.html