AuthenticationRequest.setProposedCredential

Set the #WebKitCredential of the proposed authentication challenge.

Set the #WebKitCredential of the proposed authentication challenge that was stored from a previous session. This should only be used by applications handling their own credential storage. (When using the default WebKit credential storage, [webkit.authentication_request.AuthenticationRequest.getProposedCredential] already contains previously-stored credentials.) Passing a null credential will clear the proposed credential.