GitLab

This runs the rotation ainmation with following conditions:
with 2 or 8 windows,
with NTP or blank page
in overview mode or normal

Bug: 952885, 919707

Change-Id: I50f0a44a3c2a3f79d9ffd0d818f59d2e660784dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1594043Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657321}