Save ping+beacon test status in temporary directory.

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

 <?php
+require_once '../../resources/portabilityLayer.php';
+
 function prettify($name) {
    return str_replace(' ', '-', ucwords(str_replace('_', ' ', str_replace('http_', '', strtolower($name)))));
 }
 
-$beaconFilename = "beacon" . (isset($_REQUEST['name']) ? $_REQUEST['name'] : "") . ".txt";
+$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 => $value) {
     if ($name === "CONTENT_TYPE" || $name === "HTTP_REFERER" || $name === "REQUEST_METHOD" || $name === "HTTP_COOKIE" || $name === "HTTP_ORIGIN") {
         if ($name === "CONTENT_TYPE") {
             $contentType = $value;
             $value = preg_replace('/boundary=.*$/', '', $value);
         }
         $headerName = prettify($name);
         fwrite($beaconFile, "$headerName: $value\n");
     }
 }
 $postdata = file_get_contents("php://input");
 if (strlen($postdata) == 0)
    $postdata = http_build_query($_POST);
 
 fwrite($beaconFile, "Length: " . strlen($postdata) . "\n");
 if (strpos($contentType, "application/") !== false) {
     $postdata = base64_encode($postdata);
 }
 
 fwrite($beaconFile, "Body: $postdata\n");
 fclose($beaconFile);
 rename($beaconFilename . ".tmp", $beaconFilename);
 foreach ($_COOKIE as $name => $value)
     setcookie($name, "deleted", time() - 60, "/");
 ?>