Auto merge of #6660 - nox:children-changed, r=jdm

Introduce VirtualMethods::children_changed()

This virtual method mimics the behaviour of mutation observers and make it more viable than the older child_inserted(), which didn't cover removed nodes and was called as many times as there were inserted nodes.

A few other shortcomings where remove_child() was called directly instead of Node::remove() were also fixed while at it.

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/6660)
<!-- Reviewable:end -->

1 files changed, 5 insertions, 4 deletions

diff --git a/components/script/dom/virtualmethods.rs b/components/script/dom/virtualmethods.rs
index 8bb62637ac6..88cc024acd5 100644
--- a/components/script/dom/virtualmethods.rs
+++ b/components/script/dom/virtualmethods.rs
@@ -35,7 +35,8 @@ use dom::document::Document;
 use dom::element::ElementTypeId;
 use dom::event::Event;
 use dom::htmlelement::HTMLElementTypeId;
-use dom::node::{Node, NodeHelpers, NodeTypeId, CloneChildrenFlag};
+use dom::node::{ChildrenMutation, CloneChildrenFlag, Node, NodeHelpers};
+use dom::node::NodeTypeId;
 
 use util::str::DOMString;
 
@@ -97,10 +98,10 @@ pub trait VirtualMethods {
         }
     }
 
-    /// Called on the parent when a node is added to its child list.
-    fn child_inserted(&self, child: &Node) {
+    /// Called on the parent when its children are changed.
+    fn children_changed(&self, mutation: &ChildrenMutation) {
         if let Some(ref s) = self.super_type() {
-            s.child_inserted(child);
+            s.children_changed(mutation);
         }
     }