Add iFrame to WordPress Widgets

wp-iframe-enable.php

<?php
/* Do not inlude the first 4 lines of this code. Only copy the code below this line. This should be
placed in your main functions.php to enable this globally, or on specific page templates */

//* Allow shortcodes to execute in widget areas
add_filter('widget_text', 'do_shortcode');

// Register function to allow shortcodes
function add_iframe($atts) {
    extract(shortcode_atts(array(
    'src' => '/'
    ), $atts));
  $theframe = '<iframe src="'.$src.'" width="100%" height="450" frameborder="0"></iframe>';
  return $theframe;
}
// Call function to allow iframe
add_shortcode('iframe', 'add_iframe');

Now you can add iframes for specific pages or Google Map embeds (which is why I was trying to get this figured out).

Example: [iframe src=http://thesiteyouwanttoshow.com] <---update the URL to be anything you want to iframe into your widget.