Media Grid: "Add New" should open and close, not just open.

See #24716.

Built from https://develop.svn.wordpress.org/trunk@29087


git-svn-id: http://core.svn.wordpress.org/trunk@28873 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/js/media-grid.js

@@ -230,7 +230,7 @@
 		},
 
 		addNewClickHandler: function() {
-			this.trigger( 'show:upload:attachment' );
+			this.trigger( 'toggle:upload:attachment' );
 		},
 
 		/**

wp-includes/js/media-views.js

@@ -5602,7 +5602,8 @@
 				AttachmentView: media.view.Attachment.Library
 			});
 
-			this.listenTo( this.controller, 'show:upload:attachment', _.bind( this.showUploader, this ) );
+			this.listenTo( this.controller, 'toggle:upload:attachment', _.bind( this.toggleUploader, this ) );
+
 			this.createToolbar();
 			this.createUploader();
 			this.createAttachments();
@@ -5744,8 +5745,12 @@
 			this.views.add( this.uploader );
 		},
 
-		showUploader: function() {
+		toggleUploader: function() {
+			if ( this.uploader.$el.hasClass( 'hidden' ) ) {
 				this.uploader.show();
+			} else {
+				this.uploader.hide();
+			}
 		},
 
 		createAttachments: function() {