Backed out changeset 558b823bb68b (bug 1741780) on devs request. CLOSED TREE

gfx/wr/webrender/src/clip.rs

@@ -2178,8 +2178,6 @@ fn add_clip_node_to_current_chain(
                 };
             }
             ClipSpaceConversion::Transform(..) => {
-                assert!(spatial_tree.is_ancestor(node.spatial_node_index, prim_spatial_node_index));
-
                 // Map the local clip rect directly into the same space as the picture
                 // surface. This will often be the same space as the clip itself, which
                 // results in a reduction in allocated clip mask size.

gfx/wr/webrender/src/spatial_tree.rs

@@ -755,31 +755,6 @@ impl SpatialTree {
         }
     }
 
-    /// Check if a given spatial node is an ancestor of another spatial node.
-    pub fn is_ancestor(
-        &self,
-        maybe_parent: SpatialNodeIndex,
-        maybe_child: SpatialNodeIndex,
-    ) -> bool {
-        // Early out if same node
-        if maybe_parent == maybe_child {
-            return false;
-        }
-
-        let mut current_node = maybe_child;
-
-        while current_node != self.root_reference_frame_index {
-            let node = self.get_node_info(current_node);
-            current_node = node.parent.expect("bug: no parent");
-
-            if current_node == maybe_parent {
-                return true;
-            }
-        }
-
-        false
-    }
-
     fn visit_node_impl_mut<F>(
         &mut self,
         index: SpatialNodeIndex,