GitLab

Moved calling to D-Bus service out of EnrollmentScreenHandler into
EnrollmentScreen. Needed because EnrollmentScreen implements
ActiveDirectoryJoinDelegate. Future CL will use that to provide dm token
to D-Bus service and to use configuration seed coming from DM server.

BUG=chromium:829361,chromium:809914

Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I606d974e3461c802b37ff88ec0658f910a3953f5
Reviewed-on: https://chromium-review.googlesource.com/1004954
Commit-Queue: Roman Sorokin <rsorokin@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551309}