Backed out changeset d77275db6419 (bug 1374178) for failure reftests/transform-3d/translatez-1a.html r=backout a=backout on a CLOSED TREE

Backs out https://github.com/servo/servo/pull/19106

components/style/values/generics/transform.rs

@@ -450,10 +450,3 @@ impl<T: ToCss> ToCss for Transform<T> {
         Ok(())
     }
 }
-
-impl<T> Transform<T> {
-    /// `none`
-    pub fn none() -> Self {
-        Transform(vec![])
-    }
-}