Disable outgoing SSDP requests when Chromecast support is disabled

[fmarier]

Users have reported that Brave makes outgoing connections on the local network to port 1900 (apparently ignoring any proxy settings):

• https://news.ycombinator.com/item?id=20294150
• https://community.brave.com/t/why-is-brave-issuing-upnp-discovery-requests/46500

This appears related to the SSDP protocol required for Chromecast support but we should make sure that these connections are turned off when that feature (see #209) is disabled.

Apparently turning off load-media-router-component-extension and media-router-cast-allow-all-ips in chrome://flags doesn't help.

[fmarier]

This bug mentions an enterprise policy (also mentioned in this bug) for disabling Chromecast entirely by adding a json file in /etc/opt/chrome/policies/managed/ containing the following:

{
  "EnableMediaRouter": false
}

[tildelowengrimm]

Is #5070 the more specific version of this?

[jumde]

@tomlowenthal - yes

[blacktop]

Is this happening again?

[jumde]

Hi @blacktop - Are you seeing this again? Could you please share the Brave Browser version and OS that you are using? Are you interacting with the Cast option when you see these requests or is this happening at start?

[blacktop]

I am not using the cast option and do not own any ChromeCasts. However, it stated happening all the time after I updated a week ago maybe?

I just now checked for an update and pulled down 1.29.77 (running on latest stable macOS x86_64) and It's still doing it.

[blacktop]

[jumde]

Thanks for your help @blacktop. We'll try to address this quickly. Issue tracked here - #17873