We are going to work around this on our end in the next Privacy Badger update. Here is a direct link to the as-of-now current version CRX that will continue exhibiting this Chrome rendering bug in the Italian locale: https://www.eff.org/files/privacy_badger-2018.4.23.crx

Able to reproduce the issue on Windows 10 and Ubuntu 14.04 using chrome reported version #66.0.3359.139 and latest canary #68.0.3423.2. Issue is not seen in OS-mac.

Bisect Information:
=====================
Good build: 66.0.3344.0
Bad Build : 66.0.3345.0

Change Log URL: 
https://chromium.googlesource.com/chromium/src/+log/43e31b80075135d513ff10a19e8293aca21a0ed0..004f3b4b4000be325307d1c409a03411aa00beaa

From the above change log suspecting below change
Change-Id: I7db52fb701bee9b017bebc70b777255601250d3a
Reviewed-on: https://chromium-review.googlesource.com/857902

skobes@ - 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.
Note: Adding stable blocker for M-66 as it seems to be a recent regression. Please feel free to remove the same if not appropriate.

Thanks...!!

Removing RBS since M66 has already shipped.

Here is another user report (Chromium Version 66.0.3359.170 (Official Build) Arch Linux (64-bit)), this time using the default English locale: https://github.com/EFForg/privacybadger/issues/2043

In case anyone was wondering, this is the observed behavior -
https://images.masto.donte.com.br/media_attachments/files/000/432/304/original/88392d23d3b6f10c.mp4

Might be an interaction between auto scrollbars and auto-resize mode (LocalFrameView::EnableAutoSizeMode).

Deleted: minimization.zip 1.0 KB

minimization.zip 1.0 KB Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b9a5701869ce7cd4667ab0b0a29f185be311a5ba

commit b9a5701869ce7cd4667ab0b0a29f185be311a5ba
Author: Steve Kobes <skobes@chromium.org>
Date: Fri Aug 24 23:49:13 2018

Fix feedback loop in extension popup autosizing.

FrameViewAutoSizeInfo should not add hypothetical vertical scrollbar
space when we already have a real vertical scrollbar.

The real scrollbar is included in the LayoutView's preferred width
(since crrev.com/397112).  If the redundant accomodation makes the
scrollbar detectably unnecessary, the next autosize reduces the width,
making it appear again.

The autosized FrameView now accomodates exactly one vertical scrollbar
in this scenario, instead of infinitely bouncing between two and zero.
The scrollbar could actually be removed even at this size, but the code
isn't smart enough to detect that.

Bug:  838150 
Change-Id: I23dce5a37faed33de978e1d2182009a2fe0c6fd1
Reviewed-on: https://chromium-review.googlesource.com/1188767
Reviewed-by: Stefan Zager <szager@chromium.org>
Commit-Queue: Steve Kobes <skobes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586062}
[modify] https://crrev.com/b9a5701869ce7cd4667ab0b0a29f185be311a5ba/third_party/blink/renderer/core/frame/frame_view_auto_size_info.cc
[modify] https://crrev.com/b9a5701869ce7cd4667ab0b0a29f185be311a5ba/third_party/blink/renderer/core/layout/scrollbars_test.cc

Should be fixed in dev channel (70.0.3534.4).