reftests: Fix linear-gradient reftest

... and add it to the Makefile

diff --git a/tests/reftests/linear-gradient.css b/tests/reftests/linear-gradient.css
index 5ec7fb94ffa93fb8a62a2b10454bbee866aeb72c..8e00bbff5834e48089843013d8d510efdb05531c 100644 (file)
--- a/tests/reftests/linear-gradient.css
+++ b/tests/reftests/linear-gradient.css
@@ -32,7 +32,7 @@
 }
 
 #reference #c {
-  background-image: linear-gradient(to bottom, red, green 10px, red 20px, green 30px, red 40px);
+  background-image: repeating-linear-gradient(to bottom, red, green 10px, red 20px, green 30px, red 40px);
 }
 
 #d {