"files.autoSave": "onFocusChange" causes issues with virtual file systems

[eamodio]

Virtual file system is not available notification when restoring opened editors

Steps:

1. Ensure you have RemoteHub insiders installed (and ensure RemoteHub stable is disabled).
2. Open a remote repository, via Open Remote Repository... from the command palette
3. Open a file from the remote repository
4. Now reload the window or close and re-open the remote repository

It seems to only happen we the "files.autoSave": "onFocusChange" set, if I remove that it works normally.

Here is the call stack of where it happens too:

[eamodio]

Another instance of this can be reproduced with Git or GitLens, but has a slightly different behavior.

Steps:

1. Edit a file, and in the SCM view, right-click on the edited file and choose Open File (HEAD)
2. Reload the workspace
3. 🐛 you will now see a save dialog for that file

[bpasero]

A regression from EditorInputCapabilities I added a few days ago. Apparently FileEditorInput can be untitled too 🐙

[eamodio]

@bpasero With today's insiders (which should have this fix), I'm still seeing the same behavior.

[bpasero]

Ok, I don't see it 🤷

[eamodio]

With the 2nd insiders release that came out today, I'm not longer seeing it. Not sure why I was before.