GitLab

chrome/services/sharing/*
- Introduced AcceptConnection, RejectConnection for accepting/rejecting
  connection with remote endpoints, AcceptConnection also pass a
  PayloadListener
- Introduced SendPayload and CancelPayload for sedning/canceling
  outgoing payloads

chrome/browser/nearby_sharing/nearby_connections_manager*
- Browser side usage of the above APIs
  NearbyConnectionsManager uses AcceptConnection to accept connection,
  and implements PadloadListener.
  For outgoing payloads, OnPayloadTransferUpdate will pass the status to
  its listeners directly
- SendPayload and CancelPayload are straight forward

Bug: 1076008
Change-Id: If32e703e1d701373df1833719214039a990fafa8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339670Reviewed-by: Alex Gough <ajgo@chromium.org>
Reviewed-by: Richard Knoll <knollr@chromium.org>
Commit-Queue: Alex Chau <alexchau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797170}