GitLab

This CL adds the release candidate of TabGroups to chrome://flags. It
also removes all the old options that are related to changing the
thumbnail aspect ratio.

Bug: 1116699
Change-Id: I658bdb20383a9169149faf645c3c4b263bed6b03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359400Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798507}