Use Typekit fonts in WordPress without plugin

functions.php

<?php

/**
 * TypeKit Fonts
 * @since Theme 1.0
 * @url http://wptheming.com/2013/02/typekit-code-snippet/
 * 
 */
function theme_typekit() {
    wp_enqueue_script( 'theme_typekit', '//use.typekit.net/xxxxxxx.js');
}
add_action( 'wp_enqueue_scripts', 'theme_typekit' );

function theme_typekit_inline() {
  if ( wp_script_is( 'theme_typekit', 'done' ) ) { ?>
    <script type="text/javascript">try{Typekit.load();}catch(e){}</script>
<?php }
}
add_action( 'wp_head', 'theme_typekit_inline' );