Handle 'appearance' as a admin bar menu parent in a backwards compatible way. fixes #19245.

git-svn-id: https://develop.svn.wordpress.org/trunk@19365 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/class-wp-admin-bar.php

@@ -112,9 +112,17 @@ class WP_Admin_Bar {
 	}
 
 	public function render() {
+
+		$back_compat_parents = array(
+			'appearance' => 'site-name',
+		);
+
 		// Link nodes to parents.
 		foreach ( $this->nodes as $node ) {
 
+			if ( isset( $back_compat_parents[ $node->parent ] ) )
+				$node->parent = $back_compat_parents[ $node->parent ];
+
 			// Handle root menu items
 			if ( empty( $node->parent ) ) {
 				$parent = $this->root;