Enable the CORS preflight for sendBeacon()

third_party/WebKit/LayoutTests/http/tests/navigation/resources/save-beacon.php

 <?php
 require_once '../../resources/portabilityLayer.php';
 
+if ($_SERVER["REQUEST_METHOD"] == "OPTIONS") {
+   header("Access-Control-Allow-Origin: http://127.0.0.1:8000");
+   header("Access-Control-Allow-Credentials: true");
+   header("Access-Control-Allow-Method: post");
+   header("Access-Control-Allow-Headers: content-type,cache-control");
+   exit();
+}
+
 function prettify($name) {
    return str_replace(' ', '-', ucwords(str_replace('_', ' ', str_replace('http_', '', strtolower($name)))));
 }
 
 $beaconFilename = sys_get_temp_dir() . "/beacon" . (isset($_REQUEST['name']) ? $_REQUEST['name'] : "") . ".txt";
 $beaconFile = fopen($beaconFilename . ".tmp", 'w');
 $httpHeaders = $_SERVER;
 ksort($httpHeaders, SORT_STRING);
 $contentType = "";
 foreach ($httpHeaders as $name => $value) {
@@ skipping 17 matching lines @@
 
 fwrite($beaconFile, "Body: $postdata\n");
 fclose($beaconFile);
 rename($beaconFilename . ".tmp", $beaconFilename);
 
 if (!array_key_exists('dontclearcookies', $_GET)) {
   foreach ($_COOKIE as $name => $value)
       setcookie($name, "deleted", time() - 60, "/");
 }
 ?>