On second thought, we're going to need the library-specific attachment view. see #21390, [22138].

git-svn-id: https://develop.svn.wordpress.org/trunk@22139 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/js/media-views.js

@@ -519,6 +519,13 @@
 		}
 	});
 
+	/**
+	 * wp.media.view.Attachment.Library
+	 */
+	media.view.Attachment.Library = media.view.Attachment.extend({
+		className: 'attachment library'
+	});
+
 	/**
 	 * wp.media.view.Attachment.Gallery
 	 */
@@ -630,6 +637,11 @@
 	 */
 	media.view.Workspace.Library = media.view.Workspace.extend({
 
+		attachmentsView: {
+			// The single `Attachment` view to be used in the `Attachments` view.
+			AttachmentView: media.view.Attachment.Library
+		},
+
 		initialize: function() {
 			media.view.Workspace.prototype.initialize.apply( this, arguments );