Customize: Add default control template for standard input types.

Re-use default template instead of introducing custom one for the Discard Changes button.

See #30738.

Built from https://develop.svn.wordpress.org/trunk@41771


git-svn-id: http://core.svn.wordpress.org/trunk@41605 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/script-loader.php

@@ -565,6 +565,7 @@ function wp_default_scripts( &$scripts ) {
 		'cancel'             => __( 'Cancel' ),
 		'close'              => __( 'Close' ),
 		'action'             => __( 'Action' ),
+		'discardChanges'     => __( 'Discard changes' ),
 		'cheatin'            => __( 'Cheatin’ uh?' ),
 		'notAllowed'         => __( 'Sorry, you are not allowed to customize this site.' ),
 		'previewIframeTitle' => __( 'Site Preview' ),