Improve precision of error messages from failed CORS checks.

LayoutTests/http/tests/xmlhttprequest/resources/access-control-allow-lists.php

Index: LayoutTests/http/tests/xmlhttprequest/resources/access-control-allow-lists.php
diff --git a/LayoutTests/http/tests/xmlhttprequest/resources/access-control-allow-lists.php b/LayoutTests/http/tests/xmlhttprequest/resources/access-control-allow-lists.php
index 8f0af5cf3ed088c58316c9158323806dec938536..e28fda8cbe648b4b11021ce6cb67dbe9c185b85d 100644
--- a/LayoutTests/http/tests/xmlhttprequest/resources/access-control-allow-lists.php
+++ b/LayoutTests/http/tests/xmlhttprequest/resources/access-control-allow-lists.php
@@ -1,9 +1,12 @@
 <?php
 
-$origin = $_GET['origin'];
-
-if ($origin != 'none')
-    header("Access-Control-Allow-Origin: $origin");
+if (isset($_GET['origin'])) {
+    header("Access-Control-Allow-Origin: " . $_GET['origin']);
+} else if (isset($_GET['origins'])) {
+    $origins = explode(',', $_GET['origins']);
+    for ($i = 0; $i < sizeof($origins); ++$i)
+         header("Access-Control-Allow-Origin: " . $origins[$i], false);
+}
 
 if (isset($_GET['headers']))
     header("Access-Control-Allow-Headers: {$_GET['headers']}");