Gnome Tweak Tool released the first 3.7.x version and it brings the extra backgrounds options (Scaled, Zoom, etc) back, after the drop of this feature in Gnome 3.6.
However this patch also pushed in 3.6 branch, so you won’t wait till the next Gnome release to get it. It is up to your distributors to include it, and I guess UGR will ship this in the next days.
Add extra background options
The bug report was from Jeremy Bicha | (#689299)
Several people have complained in webupd8.org about the lack of background options in System Settings 3.6.
org.gnome.desktop.background picture-options and picture-uri in particular are the most requested.
The fix came from John Stowers | (commit)
This problem has been fixed in the development version. The fix will be available in the next major software release. Thank you for your bug report.
I also cherrypicked the patch onto the 3-6 branch (so you can push an updated tweak tool to ubuntu users)
This is how it looks
You can select your background and apply one of the 6 filters (Zoom, Wallpaper, Stretched, Spanned, Scaled, Center) or None, which is the default. If you select a background here, this is also applied in System Settings Backgrounds, and vice versa.
Jeremy is the author of UGR, (which by the way seems to have great success), he is also member of Ubuntu Gnome3 Team, and a contributor to Gnome. I didn’t ask him, but it would be a surprise if he won’t push these changes in UGR ;)