Sort header names in Access-Control-Request-Headers

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

Index: LayoutTests/http/tests/xmlhttprequest/resources/access-control-preflight-request-header-sorted.php
diff --git a/LayoutTests/http/tests/xmlhttprequest/resources/access-control-preflight-request-header-sorted.php b/LayoutTests/http/tests/xmlhttprequest/resources/access-control-preflight-request-header-sorted.php
new file mode 100644
index 0000000000000000000000000000000000000000..fb44c44b99f850d26b5b5384424a2bba1836104a
--- /dev/null
+++ b/LayoutTests/http/tests/xmlhttprequest/resources/access-control-preflight-request-header-sorted.php
@@ -0,0 +1,22 @@
+<?php
+if ($_SERVER["REQUEST_METHOD"] == "OPTIONS") {
+    // Check that the names in Access-Control-Request-Headers are
+    // "sorted lexicographically, and byte lowercased".
+    // Fetch API Spec: https://fetch.spec.whatwg.org/#cors-preflight-fetch-0
+    if ($_SERVER["HTTP_ACCESS_CONTROL_REQUEST_HEADERS"] ==
+        'x-custom-s, x-custom-test, x-custom-u, x-custom-ua, x-custom-v') {
+        header("Access-Control-Allow-Headers: x-custom-s, x-custom-test, x-custom-u, x-custom-ua, x-custom-v");
+    } else {
+        header("HTTP/1.1 400");
+    }
+    header("Access-Control-Allow-Origin: *");
+    header("Access-Control-Max-Age: 0");
+} else if ($_SERVER["REQUEST_METHOD"] == "GET") {
+    header("Access-Control-Allow-Origin: *");
+    header("Access-Control-Max-Age: 0");
+    if (isset($_SERVER["HTTP_X_CUSTOM_S"]))
+        echo "PASS";
+    else
+        echo "FAIL";
+}
+?>