GitLab

This CL converts SubscriberPtr and SubscriberRequest
to new Mojo types using PendingRemote or Remote,
RemoteSet, PendingReceiver, and ReceiverSet.

It also updates RegisterSubscriber, Connect, and
Clone from app_service.mojom.

Bug: 955171
Change-Id: I3de5fe264d54ba707966f5cecde4c9d0778c6911
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1821498Reviewed-by: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Oksana Zhuravlova <oksamyt@chromium.org>
Commit-Queue: Julie Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#699696}