The API described in #7117 is primarily used by extensions to block resources that served from many different domains to circumvent traditional adblocking techniques. Similarly, Brave's most important use-case for the DNS resolution API is to integrate it with Shields.

Shields should block any network requests where either the original URL or that URL's canonical name (DNS CNAME record) matches any adblock rules.

Since our network blocking is done in C++ code, this doesn't necessarily need to be exposed as a Javascript API.