Fix bug where tab hover card's title and domain could refer to different pages.

Tab renderer data's visible url will show the domain of the page the user is navigating to before there is a title. So at times the title would be for the page the user is navigating from while the url was for the page the user was navigating to. Using the last committed url will prevent this title and domain from being out of sync.

Bug: 910739
Change-Id: I19f88d3a96ec950d37476f3287381ec2409ec17b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1632593
Commit-Queue: Caroline Rising <corising@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663940}