diff -r 000000000000 -r 6474c204b198 layout/reftests/w3c-css/submitted/variables/support/external-variable-supports.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/reftests/w3c-css/submitted/variables/support/external-variable-supports.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,4 @@
+body { color: red; }
+@supports (color:var(--a)) {
+  p { color: green; }
+}