We can probably re-use the same logic, but instead of calling through to the Cast MRP we can start the in-browser discovery service.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7818c96d72777c7d68f750a4ffa80cd611e306e4

commit 7818c96d72777c7d68f750a4ffa80cd611e306e4
Author: Derek Cheng <imcheng@chromium.org>
Date: Thu Dec 14 00:01:03 2017

[Media Router] Gate mDNS discovery on Windows.

mDNS discovery can trigger a firewall prompt on a fresh user-level
Chrome install on Windows or if there are no existing firewall rules
for mDNS traffic(?). This patch applies the same gating logic to
the mdns logic in in-browser cast discovery.

TODO: merge this patch back to M64.

Bug:  794317 
Change-Id: I5df1a2f60eb3a8411b642fc8996f2e0279912401
Reviewed-on: https://chromium-review.googlesource.com/823244
Commit-Queue: Derek Cheng <imcheng@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523942}
[modify] https://crrev.com/7818c96d72777c7d68f750a4ffa80cd611e306e4/chrome/browser/media/router/discovery/mdns/cast_media_sink_service.cc
[modify] https://crrev.com/7818c96d72777c7d68f750a4ffa80cd611e306e4/chrome/browser/media/router/discovery/mdns/cast_media_sink_service.h
[modify] https://crrev.com/7818c96d72777c7d68f750a4ffa80cd611e306e4/chrome/browser/media/router/mojo/media_router_desktop.cc
[modify] https://crrev.com/7818c96d72777c7d68f750a4ffa80cd611e306e4/chrome/browser/media/router/mojo/media_router_desktop.h
[modify] https://crrev.com/7818c96d72777c7d68f750a4ffa80cd611e306e4/chrome/browser/media/router/mojo/media_router_desktop_unittest.cc

This bug requires manual review: M64 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), kbleicher@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

verified this on canary 65.0.3295.0

Approving merge to M64. Branch:3282

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2f4d6d47ee2eccd523c244d837b1762e80e672d9

commit 2f4d6d47ee2eccd523c244d837b1762e80e672d9
Author: Derek Cheng <imcheng@chromium.org>
Date: Fri Dec 15 20:36:08 2017

[Media Router] Gate mDNS discovery on Windows.

mDNS discovery can trigger a firewall prompt on a fresh user-level
Chrome install on Windows or if there are no existing firewall rules
for mDNS traffic(?). This patch applies the same gating logic to
the mdns logic in in-browser cast discovery.

TODO: merge this patch back to M64.

TBR=imcheng@chromium.org

(cherry picked from commit 7818c96d72777c7d68f750a4ffa80cd611e306e4)

Bug:  794317 
Change-Id: I5df1a2f60eb3a8411b642fc8996f2e0279912401
Reviewed-on: https://chromium-review.googlesource.com/823244
Commit-Queue: Derek Cheng <imcheng@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#523942}
Reviewed-on: https://chromium-review.googlesource.com/830666
Reviewed-by: Derek Cheng <imcheng@chromium.org>
Cr-Commit-Position: refs/branch-heads/3282@{#243}
Cr-Branched-From: 5fdc0fab22ce7efd32532ee989b223fa12f8171e-refs/heads/master@{#520840}
[modify] https://crrev.com/2f4d6d47ee2eccd523c244d837b1762e80e672d9/chrome/browser/media/router/discovery/mdns/cast_media_sink_service.cc
[modify] https://crrev.com/2f4d6d47ee2eccd523c244d837b1762e80e672d9/chrome/browser/media/router/discovery/mdns/cast_media_sink_service.h
[modify] https://crrev.com/2f4d6d47ee2eccd523c244d837b1762e80e672d9/chrome/browser/media/router/mojo/media_router_desktop.cc
[modify] https://crrev.com/2f4d6d47ee2eccd523c244d837b1762e80e672d9/chrome/browser/media/router/mojo/media_router_desktop.h
[modify] https://crrev.com/2f4d6d47ee2eccd523c244d837b1762e80e672d9/chrome/browser/media/router/mojo/media_router_desktop_unittest.cc