They reduced the number of patches quite a bit. For some of the things they do, they depend on components that are not commonly used within GNOME. Meaning, it's

They reduced the number of patches quite a bit. For some of the things they do, they depend on components that are not commonly used within GNOME. Meaning, it's not a patch, but as a sole user they'll have to maintain components if they're the only "user". Something written on top of Tracker IIRC; not started by Canonical, but nicely used by them. That's always a bit of a difficult explanation, sometimes Canonical expects maintenance to happen magically.