GitLab

Track share targets as they are (un)registered, and start scanning.
Only handles surfaces registered to the foreground for now.

Bug: 1084644
Change-Id: I852388f8dd1d355263979d94f2959cc79f905929
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2292214
Commit-Queue: Naomi Musgrave <nmusgrave@chromium.org>
Reviewed-by: Richard Knoll <knollr@chromium.org>
Reviewed-by: Alex Chau <alexchau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796384}