GitLab

This is for SWA version to control its window state just as we did in
Chrome App Window API.

Bug: 980846
Test: Tested with previous CLs to make sure the window state is
controllable in the SWA version of CCA.

Change-Id: Ib757e78ed0d9a9bec23f1e78c5a257d6e312bc4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2257084
Commit-Queue: Wei Lee <wtlee@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Inker Kuo <inker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822610}