The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/83241c8d86e2740d191bcecfc5d318820d9b6140

commit 83241c8d86e2740d191bcecfc5d318820d9b6140
Author: Bin Zhao <zhaobin@chromium.org>
Date: Fri Mar 09 21:20:49 2018

[DIAL] Restart timer even if there is not DIAL device

There is a bug that when we switch from network1 to network2, DIAL devices
from network1 stays on MR dialog.

Current implementation will not restart the timer and notify
extension about sink list changes if network2 has no DIAL device.

Fix it by always restart time when we get DIAL device events from
DIAL registry.

Bug:  820215 
Change-Id: Ia149778427f142bffbb9ebd61b0de920b7a54289
Reviewed-on: https://chromium-review.googlesource.com/956310
Reviewed-by: Derek Cheng <imcheng@chromium.org>
Commit-Queue: Bin Zhao <zhaobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542230}
[modify] https://crrev.com/83241c8d86e2740d191bcecfc5d318820d9b6140/chrome/browser/media/router/discovery/dial/dial_media_sink_service_impl.cc
[modify] https://crrev.com/83241c8d86e2740d191bcecfc5d318820d9b6140/chrome/browser/media/router/discovery/dial/dial_media_sink_service_impl.h
[modify] https://crrev.com/83241c8d86e2740d191bcecfc5d318820d9b6140/chrome/browser/media/router/discovery/dial/dial_media_sink_service_impl_unittest.cc

Please verify change

Specifically, please verify that the fix landed and fixed the issue.  Thanks!

verified fixed in 67.0.3370.0