GitLab

If an executable is run with "-d" and either the flag --fuchsia-out-dir
or the GN arg default_fuchsia_build_dir_for_installation are set,
the runner script will publish to the Fuchsia output directory's
Amber repository and rely on an existing instance of "fx serve" for
delivering the package to the target.

Encapsulates Amber repo interactions into a new abstract class, AmberRepo.
Adds two concrete classes, one for ephemeral repos (used by emulator runs),
and one for external repos (used for publishing to devices or persistent
Fuchsia AEMU instances.)

Bug: 1022002
Change-Id: Ieb330dd8cd92239c1c5341741ef559483af3285b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1907488
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714636}