Chrome Version: 71.0.3557.0
OS: Win10, Linux, Chrome

What steps will reproduce the problem?
(1) Sign-out of chrome OR Disable -- chrome://flags/#enable-autofill-credit-card-upload
(2) Enable -- chrome://flags/#enable-autofill-save-card-sign-in-after-local-save
(3) Go to https://dump-truck.appspot.com/usecase-cc/cc.html
(4) Fill form and hit submit.
(5) Accept save card offer.
(6) While "Card saved" text is animating, click on credit card icon.

What is the expected result?

  The highlight is rounded.
  Expected: https://screenshot.googleplex.com/Ns5z00hrXvF

What happens instead?

  The highlight has a straight edge on the right.
  Actual: https://screenshot.googleplex.com/fDYB2dWc0c9



Note, issue also happens with Pop-up blocker, but animation pauses and is too fast to notice. But if clicked on at the right time, we get this result: https://screenshot.googleplex.com/yGS9Mqgokkx