GitLab

- Adds row to c/b/r/settings/device_page/storage for Crostini storage.

- Fixes method ordering in device_storage_handler.

Bug: 822499
Change-Id: Ibc0d01c287bf49af639f98803257c05aa66a0d1d
Reviewed-on: https://chromium-review.googlesource.com/1077912
Commit-Queue: Renée Wright <rjwright@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567572}