Set tab hover cards anchor_view_ to null when animation has ended or been stopped.

This is a follow up to https://chromium-review.googlesource.com/c/chromium/src/+/1627654

Bug: 910739
Change-Id: Ie80bc128250fd4dde9763fd38ce5bcfc58669d31
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627666
Commit-Queue: Caroline Rising <corising@chromium.org>
Reviewed-by: Dana Fried <dfried@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662868}
1 file changed