Increase the lifetime of Navigation Preload related objects.

third_party/WebKit/LayoutTests/http/tests/serviceworker/navigation-preload/resources/chunked-encoding-scope.php

Index: third_party/WebKit/LayoutTests/http/tests/serviceworker/navigation-preload/resources/chunked-encoding-scope.php
diff --git a/third_party/WebKit/LayoutTests/http/tests/serviceworker/navigation-preload/resources/chunked-encoding-scope.php b/third_party/WebKit/LayoutTests/http/tests/serviceworker/navigation-preload/resources/chunked-encoding-scope.php
new file mode 100644
index 0000000000000000000000000000000000000000..c70ce320f421ad65c37f7bcb2052ddd3b929edcd
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/http/tests/serviceworker/navigation-preload/resources/chunked-encoding-scope.php
@@ -0,0 +1,18 @@
+<?php
+  function put_chunk($txt) {
+    echo sprintf("%x\r\n", strlen($txt));
+    echo "$txt\r\n";
+  }
+  header("Content-type: text/html; charset=UTF-8");
+  header("Transfer-encoding: chunked");
+  ob_flush();
+  flush();
+  usleep(10000);

[falken, 2017/01/18 14:24:59]

Can you comment why we need usleep and how you chose 10,000? BTW
https://cs.chromium.org/chromium/src/third_party/WebKit/LayoutTests/http/test...
used 1000 us.

[horo, 2017/01/18 16:14:57]

Done.

But I have no specific reason to chose 10,000.

+  for ($i = 0; $i < 10; $i++) {
+    put_chunk("$i");
+    ob_flush();
+    flush();
+    usleep(10000);
+  }
+  echo "0\r\n\r\n";
+?>