Pass a WebRTC AsyncResolverFactory to the standalone RTCIceTransport

This allows the mDNS experiment to work for the standalone
RTCIceTransport in addition to the ICE transports created by the
RTCPeerConnection.

Bug: 927579
Change-Id: I75d1bbb7f469d3282a984cae346a096229b3d08b
Reviewed-on: https://chromium-review.googlesource.com/c/1449320
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Henrik Boström <hbos@chromium.org>
Commit-Queue: Steve Anton <steveanton@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#628443}(cherry picked from commit bb81774be8f11e535ded48c144b65690f06b2a05)
Reviewed-on: https://chromium-review.googlesource.com/c/1452697
Reviewed-by: Steve Anton <steveanton@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#174}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
9 files changed