Index: wp-includes/css/buttons.css
===================================================================
--- wp-includes/css/buttons.css	(revision 22635)
+++ wp-includes/css/buttons.css	(working copy)
@@ -49,6 +49,7 @@
 	border-width: 1px;
 	border-style: solid;
 	-webkit-border-radius: 3px;
+	-webkit-appearance: none;
 	border-radius: 3px;
 	white-space: nowrap;
 	-webkit-box-sizing: border-box;