gtk_snapshot_pop() => removed gtk_snapshot_pop_and_append() => gtk_snapshot_pop() So now there is no way to get a rendernode out of the snapshotting API until you gtk_snapshot_finish().
We're not just using this for icon filters, but for regular filters, so the existing name is confusing.
This uses the new GskColorMatrixNode to implement a filter that applies to icons. It's meant to replace -gtk-icon-effect.
