Index: wp-includes/css/media-views.css
===================================================================
--- wp-includes/css/media-views.css	(revision 23031)
+++ wp-includes/css/media-views.css	(working copy)
@@ -547,7 +547,8 @@
 	overflow: hidden;
 }
 
-.media-iframe iframe {
+.media-frame .media-iframe,
+.media-frame .media-iframe iframe {
 	height: 100%;
 	width: 100%;
 }