In Firefox, style placeholder text a dark gray since the browser doesn't do it for us. props helenyhou, fixes #22689.

git-svn-id: http://core.svn.wordpress.org/trunk@22986 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/css/wp-admin.css

@@ -750,6 +750,10 @@ input[readonly] {
 	background-color: #eee;
 }
 
+:-moz-placeholder {
+   color: #a9a9a9;
+}
+
 /*------------------------------------------------------------------------------
   1.0 - Text Styles
 ------------------------------------------------------------------------------*/

wp-includes/css/media-views.css

@@ -65,6 +65,10 @@
 	-webkit-appearance: textfield;
 }
 
+.media-frame :-moz-placeholder {
+   color: #a9a9a9;
+}
+
 /* Enable draggable on IE10 touch events until it's rolled into jQuery UI core */
 .ui-sortable,
 .ui-draggable {