diff -r 000000000000 -r 6474c204b198 layout/reftests/margin-collapsing/block-xml-root-1.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/reftests/margin-collapsing/block-xml-root-1.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,10 @@
+root {
+ display: block;
+ margin: 20px 0;
+}
+leaf {
+ display: block;
+ background-color: green;
+ margin: 10px 0;
+ height: 100px;
+}