Move `toolbar` declaration after the `:visible` check, like it was before [28019].

props kovshenin.
fixes #24859.
Built from https://develop.svn.wordpress.org/trunk@28046


git-svn-id: http://core.svn.wordpress.org/trunk@27876 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/js/media-views.js

@@ -4903,13 +4903,14 @@
 
 		scroll: function() {
 			var view = this,
-				toolbar = this.views.parent.toolbar;
+				toolbar;
 
-			// @todo: is :visible still necessary?
 			if ( ! this.$el.is(':visible') || ! this.collection.hasMore() ) {
 				return;
 			}
 
+			toolbar = this.views.parent.toolbar;
+
 			// Show the spinner only if we are close to the bottom.
 			if ( this.el.scrollHeight - ( this.el.scrollTop + this.el.clientHeight ) < this.el.clientHeight / 3 ) {
 				toolbar.get('spinner').show();