GitLab

Distribute a little more logic from the shelf layout manager to
individual shelf components where it belongs. Now that most coordinates
are calculated within the screen, moving this logic around is a lot
easier.

Change-Id: Ib682350c7bcea935ddea21918b8ba09e3903a367
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2066107
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743135}