Add mojom for connecting to video capture service.

This mojom file defines an interface for establishing a direct
connection to the video capture service in Chrome. The media perception
service (running on Chrombox for Meetings devices) will use this API to
do device selection and read frames, etc.

As part of starting the media perception service, we establish a Mojo
IPC connection so that the service can talk to the video capture
service.

Bug: 842718, 799739
Change-Id: I1a51fad4a4e38b75c8503eb4775c1aa4b4b42fa2
Reviewed-on: https://chromium-review.googlesource.com/1042460
Commit-Queue: Luke Sorenson <lasoren@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Reviewed-by: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Toni Barzic <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576598}
14 files changed