There are quite a few potential causes in the changelist. I am particularly suspecting one of the ones related to filters because it seems that the broken one has a blurry edge and the non-broken one does not. We need a bisect to narrow it down to a specific patch.

In particular, https://chromium.googlesource.com/chromium/src/+/05c8461dff1ce44b6bb1d2675492078d332bd209 enables filters that would previously have been considered errors.

If that is indeed the cause, then this is may be a web site problem and not a Chrome problem.

Narrow Bisect:
https://chromium.googlesource.com/chromium/src/+log/57da1c75484e5a3f0af03d038c43e6f23e1549e8..a6085a6a3f95d949f7b81361c901816c5e4a8dcf?pretty=fuller&n=100

Suspecting: r419203 ?

Please re-assign if your change is not the cause of this issue.

This is not a regression. Rather it is a deliberate change that has quality problems. Next step is to for estade@ to determine if it's a bug in the change they made or if it has revealed an issue in Skia painting.

yea, it's a bug --- described by  bug 656662 

shouldn't really be necessary to port the fix to m55 as the flag is non-default there.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b1448a03ddd9c30a6711cb485ba0614a5e41579e

commit b1448a03ddd9c30a6711cb485ba0614a5e41579e
Author: estade <estade@chromium.org>
Date: Thu Oct 20 19:52:12 2016

Harmony - Draw bubble/dialog borders just outside the content area
instead of just inside of it.

As noted in code comments, this creates minor graphical bugs at scale
factors greater than 1, but I don't think they can be addressed at the
moment.

BUG= 655589 , 656662 

Review-Url: https://chromiumcodereview.appspot.com/2439793002
Cr-Commit-Position: refs/heads/master@{#426570}

[modify] https://crrev.com/b1448a03ddd9c30a6711cb485ba0614a5e41579e/ui/views/bubble/bubble_border.cc

should be fixed