service worker: Fix the type of an update promise reject value

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/update-worker.php

 <?php
 if(!isset($_COOKIE['mode']))
   $mode = 'init'; // Set mode to 'init' for initial fetch.
 else
   $mode = $_COOKIE['mode']; // $_COOKIE['mode'] is either 'normal' or 'error'.
 
 // no-cache itself to ensure the user agent finds a new version for each update.
 header("Cache-Control: no-cache, must-revalidate");
 header("Pragma: no-cache");
 
+$extra_body = '';
+
 if ($mode == 'init') {
   // Set a normal mimetype.
   // Set cookie value to 'normal' so the next fetch will work in 'normal' mode.
   header('Content-Type:application/javascript');
   setcookie('mode', 'normal');
 } else if ($mode == 'normal') {
   // Set a normal mimetype.
   // Set cookie value to 'error' so the next fetch will work in 'error' mode.
   header('Content-Type:application/javascript');
   setcookie('mode', 'error');
 } else if ($mode == 'error') {
   // Set a disallowed mimetype.
+  // Set cookie value to 'syntax-error' so the next fetch will work in 'syntax-error' mode.
+  header('Content-Type:text/html');
+  setcookie('mode', 'syntax-error');
+} else if ($mode == 'syntax-error') {
+  // Set cookie value to 'throw-install' so the next fetch will work in 'throw-install' mode.
+  header('Content-Type:application/javascript');
+  setcookie('mode', 'throw-install');
+  $extra_body = 'badsyntax(isbad;';
+} else if ($mode == 'throw-install') {
   // Unset and delete cookie to clean up the test setting.
-  header('Content-Type:text/html');
+  header('Content-Type:application/javascript');
   unset($_COOKIE['mode']);
   setcookie('mode', '', time() - 3600);
+  $extra_body = "addEventListener('install', function(e) { throw new Error('boom'); });";
 }
 // Return a different script for each access.
-echo '// ' . microtime();
+echo '/* ', microtime(), ' */ ', $extra_body;
 ?>