0905650fec
There was some discussion on whether the XULStore data should be written back into Session Store or Prefs. My concern there is that since we no longer *write* to XULStore, there is a good chance that this data is outdated anyways, and we'd be overwriting data in other places that *are* up-to-date. My vote is to simply discard this data, it seems that users were already comfortable with clearing their xulstore.json, so it doesn't seem like an issue to do the same programmatically. Differential Revision: https://phabricator.services.mozilla.com/D248476