Allows you to add more fonts to Shop Front's typography plugin

gistfile1.php

function shopfront_child_theme_site_title_fonts( $fonts ) {

    // the font-name must match the google font name exactly as shown on https://edgewebfonts.adobe.com/fonts
    $fonts['pt-sans'] = 'PT Sans';
    $fonts['droid-sans'] = 'Droid Sans';

    return $fonts;
}
add_filter( 'shopfront_typography_site_title_fonts', 'shopfront_child_theme_site_title_fonts' );