auto merge of #646 : kmcallister/servo/incremental-layout, r=metajack

This is a first attempt at incremental layout.  When recomputing styles, we compare old and new CSS properties to determine which layout steps can be skipped.

Since I'm new to Servo I'm not sure that my code matches the idioms of the project.  Please don't hold back with review comments :)

1 files changed, 6 insertions, 9 deletions

diff --git a/src/components/main/css/select_handler.rs b/src/components/main/css/select_handler.rs
index be7b21b3924..4a294aa2426 100644
--- a/src/components/main/css/select_handler.rs
+++ b/src/components/main/css/select_handler.rs
@@ -30,17 +30,14 @@ impl SelectHandler<AbstractNode<LayoutView>> for NodeSelectHandler {
 
     fn named_parent_node(&self, node: &AbstractNode<LayoutView>, name: &str)
                          -> Option<AbstractNode<LayoutView>> {
-        match node.parent_node() {
-            Some(parent) => {
-                do with_node_name(parent) |node_name| {
-                    if eq_slice(name, node_name) {
-                        Some(parent)
-                    } else {
-                        None
-                    }
+        do node.parent_node().chain |parent| {
+            do with_node_name(parent) |node_name| {
+                if eq_slice(name, node_name) {
+                    Some(parent)
+                } else {
+                    None
                 }
             }
-            None => None
         }
     }