Add a document.addCertException function to about:certerror pages, and use it on the desktop certerror page.
Also, as the CallerIsTrusted* functions expect URLs like about:certerror, but GeckoView error pages are data URLs, and so need to be handled differently for these special error-page methods to be exposed on their documents.
Example usage of document.addCertException:
document.addCertException(
true|false /* true == temporary, false == permanent */
).then(
() => {
location.reload();
},
err => {
console.error(err);
}
);
Differential Revision: https://phabricator.services.mozilla.com/D56974