Sort header names in Access-Control-Request-Headers

LayoutTests/http/tests/xmlhttprequest/resources/access-control-preflight-request-header-lowercase.php

 <?php
-require_once '../../resources/portabilityLayer.php';
-
 header("Access-Control-Allow-Origin: *");
 header("Access-Control-Max-Age: 0");
 
 if ($_SERVER["REQUEST_METHOD"] == "OPTIONS") {
     // Split the Access-Control-Request-header value based on the token.
     $accessControlRequestHeaderValues = explode(", ", $_SERVER["HTTP_ACCESS_CONTROL_REQUEST_HEADERS"]);
     if (in_array("x-custom-header", $accessControlRequestHeaderValues)) // Case-sensitive comparison to make sure that browser sends the value in lowercase.
         header("Access-Control-Allow-Headers: X-Custom-Header");  // Add "Access-Control-Allow-Headers: X-Custom-Header" to "OPTIONS" response.
 
 } else if ($_SERVER["REQUEST_METHOD"] == "GET") {
     if (isset($_SERVER["HTTP_X_CUSTOM_HEADER"]))
         echo "PASS";
     else
         echo "FAIL";
 }
 ?>