We now create the listener after receiving a "browsing-context-did-set-embedder" and destroy it after receiving "browsing-context-discarded". Differential Revision: https://phabricator.services.mozilla.com/D110337
We now create the listener after receiving a "browsing-context-did-set-embedder" and destroy it after receiving "browsing-context-discarded". Differential Revision: https://phabricator.services.mozilla.com/D110337