Able to reproduce the issue on reported chrome version 69.0.3497.23 using Windows 10. As the issue isn't seen in 60.0.3112.0 considering it as Non-Regression(...Hence adding label Needs-Bisect) and tentatively marking it as Untriaged. 
Note: Will update the bisect information soon.

Thanks! 

++Issue is seen on latest canary 70.0.3516.0 too, using Mac 10.13.1 and Ubuntu 14.04

Bisect Information:
--------------------
Good Build: 69.0.3443.0
Bad Build:  69.0.3444.0

You are probably looking for a change made after 562238 (known good), but no later than 562239 (first known bad).
CHANGELOG URL:
 https://chromium.googlesource.com/chromium/src/+log/53ce5696671da9931a1cb01d602128ef1a95db74..6fe326cd80cd13676bbb45ba47bb5c9754989bfe
Suspecting: https://chromium.googlesource.com/chromium/src/+/6fe326cd80cd13676bbb45ba47bb5c9754989bfe
Review URL: https://chromium-review.googlesource.com/1072650

@Rune Lillesveen: Please help in assigning it to the right owner, if this is not related to your change.
Note: As this seems to be a recent regression, adding RB-Stable for M-69, please remove/change if not required.

Thanks!

Reverting that change fixes this issue.

Pls provide link to revert CL.

Also how safe is the revert to merge to M69? If revert is ready and safe to merge to M69, pls request a merge to M69 ASAP.

Much simpler to fix than revert:

https://chromium-review.googlesource.com/c/chromium/src/+/1172140

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dbcb1e96fe94ba00f555422ac717a459620674c0

commit dbcb1e96fe94ba00f555422ac717a459620674c0
Author: Rune Lillesveen <futhark@chromium.org>
Date: Mon Aug 13 10:21:16 2018

Missing call to DidRecalcStyle for TextControlElement base.

Was lost when introducing override in HTMLInputElement in [1].

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1072650

Bug:  871249 
Change-Id: I9f33c88913dd00bf9f301b02fdb99bc43ecf82c6
Reviewed-on: https://chromium-review.googlesource.com/1172140
Reviewed-by: Anders Ruud <andruud@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582540}
[modify] https://crrev.com/dbcb1e96fe94ba00f555422ac717a459620674c0/third_party/blink/renderer/core/html/forms/html_input_element.cc
[modify] https://crrev.com/dbcb1e96fe94ba00f555422ac717a459620674c0/third_party/blink/renderer/core/html/forms/html_input_element_test.cc

[Auto-generated comment by a script] We noticed that this issue is targeted for M-69; 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-69 label, otherwise remove Merge-TBD label. Thanks.

Cl listed at #7 is not in canary yet, pls update the bug with canary result tomorrow. Thank you.

This bug requires manual review: M69 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), kariahda@(iOS), cindyb@(ChromeOS), govind@(Desktop)

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

The NextAction date has arrived: 2018-08-14

The jsfiddle from the description works in Mac Canary 70.0.3522.0

Approving merge to M69 branch 3497 based on comment #15 and per offline chat with  futhark@, this should be a safe merge. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c479e45510f6b78a6d2ca0770aa624bb5bde9112

commit c479e45510f6b78a6d2ca0770aa624bb5bde9112
Author: Rune Lillesveen <futhark@chromium.org>
Date: Tue Aug 14 17:41:44 2018

Missing call to DidRecalcStyle for TextControlElement base.

Was lost when introducing override in HTMLInputElement in [1].

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1072650

Bug:  871249 
Change-Id: I9f33c88913dd00bf9f301b02fdb99bc43ecf82c6
Reviewed-on: https://chromium-review.googlesource.com/1172140
Reviewed-by: Anders Ruud <andruud@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#582540}(cherry picked from commit dbcb1e96fe94ba00f555422ac717a459620674c0)
Reviewed-on: https://chromium-review.googlesource.com/1174752
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/branch-heads/3497@{#618}
Cr-Branched-From: 271eaf50594eb818c9295dc78d364aea18c82ea8-refs/heads/master@{#576753}
[modify] https://crrev.com/c479e45510f6b78a6d2ca0770aa624bb5bde9112/third_party/blink/renderer/core/html/forms/html_input_element.cc
[modify] https://crrev.com/c479e45510f6b78a6d2ca0770aa624bb5bde9112/third_party/blink/renderer/core/html/forms/html_input_element_test.cc