Implement navigator.sendBeacon()

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

Index: LayoutTests/http/tests/navigation/resources/check-beacon.php
diff --git a/LayoutTests/http/tests/navigation/resources/check-beacon.php b/LayoutTests/http/tests/navigation/resources/check-beacon.php
new file mode 100644
index 0000000000000000000000000000000000000000..aadf62a2674c46c6c1743f19a7d5bb544512bf60
--- /dev/null
+++ b/LayoutTests/http/tests/navigation/resources/check-beacon.php
@@ -0,0 +1,19 @@
+<?php
+$beaconFilename = "beacon" . (isset($_REQUEST['name']) ? $_REQUEST['name'] : "") . ".txt";
+while (!file_exists($beaconFilename)) {
+    usleep(10000);
+    // file_exists() caches results, we want to invalidate the cache.
+    clearstatcache();
+}
+
+header('Content-Type: text/plain');
+echo "Beacon sent successfully\n";
+$beaconFile = fopen($beaconFilename, 'r');
+while ($line = fgets($beaconFile)) {
+    $trimmed = trim($line);
+    if ($trimmed != "")
+        echo "$trimmed\n";
+}
+fclose($beaconFile);
+unlink($beaconFilename);
+?>