third_party/WebKit/LayoutTests/http/tests/security/resources/green-if-referrer-is-origin.php

<?php
header('Content-Type: image/png');
if ($_SERVER['HTTP_REFERER'] != 'http://127.0.0.1:8000/') {
    $img = 'red200x100.png';
} else {
    $img = 'green250x50.png';
}
echo file_get_contents($img);
?>