buffet: Refactor async operations.

Use less of lambdas and keep the logic in methods.

BUG=None
TEST=cros_workon_make buffet --test&&manual

Change-Id: I6bc3bddaa69763b029af6960630b1bd1e5f5c30e
Reviewed-on: https://chromium-review.googlesource.com/225960
Reviewed-by: Anton Muhin <antonm@chromium.org>
Commit-Queue: Anton Muhin <antonm@chromium.org>
Tested-by: Anton Muhin <antonm@chromium.org>
2 files changed
tree: a141df6cea2c9c620dea1413f11d631438ee6987
  1. buffet/