diff -r 000000000000 -r 6474c204b198 layout/reftests/css-valid/button/style.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/reftests/css-valid/button/style.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+/* Override default style */
+button:invalid {
+  box-shadow: none;
+}
+
+button.notvalid {
+  background-color: green;
+}
+button.notvalid:valid {
+  background-color: red;
+}
+
+button.valid {
+  background-color: red;
+}
+button.valid:valid {
+  background-color: green;
+}