Index: wp-admin/css/customize-controls.css
===================================================================
--- wp-admin/css/customize-controls.css	(revision 29333)
+++ wp-admin/css/customize-controls.css	(working copy)
@@ -36,11 +36,6 @@
 	border-bottom: 1px solid #ddd;
 }
 
-#customize-controls .wp-full-overlay-sidebar-content {
-	overflow-y: auto;
-	overflow-x: hidden;
-}
-
 #customize-info {
 	border: none;
 	border-top: 1px solid #ddd;