GitLab

Convert Crostini to a class, and move state into bg so that all
FilesApp windows will have a consistent view of which paths are shared.

Bug: 878324
Change-Id: I3c21465b625091fd6360e6b799d9e85baf1ea614
Reviewed-on: https://chromium-review.googlesource.com/c/1335747
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608270}