33a3d37016
When we duplicate a tab, we don't need to have about:blank load in it, because we are going to use restore mechanism to copy data into the new tab. If we don't skip the superfluous load, the restoring process might race with the loading of about:blank, and sometimes we might try to destroy the WindowGlobalChild actor just as SessionStore is trying to restore docshell capabilities for that tab resulting in a rejected promise in _restoreHistory and `_restoreHistoryComplete` not getting called. Differential Revision: https://phabricator.services.mozilla.com/D119313
