GitLab

Move launchFileManager() from `launcher` namespace and registerDialog()
from global namespace to the interface FileBrowserBackgroundFull.

This keeps consistent all access from foreground page going through this
interface.

Bug: 1133186
Change-Id: I342af2db0aaec75843a9dccff777a6da29d3b9b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2613848Reviewed-by: Jeremie Boulic <jboulic@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841330}