postEditMobile is being replaced by postEdit in https://gerrit.wikimedia.org/r/c/mediawiki/extensions/MobileFrontend/+/915840. The two hooks behave somewhat differently so we need to make sure our hook handlers don't break.
- StructuredTaskSaveDialog: I think we just need to drop the OO.ui.isMobile() branch. Probably needs to happen on the same train as the MobileFrontend patch, I don't see an easy way to make it work with both versions.
- SuggestedEditSession: nothing to do here, I think. The data.newRevId === null branch will be handled by StructuredTaskSaveDialog instead. newRevId will be loaded on demand via API since the postEdit hook doesn't provide it. The nextRequest isn't needed since postEdit runs reliably after the reload (?).
- I don't think MidEditSignup is affected.