service worker: registration-mime-types.https.html could be slow

Add a meta tag to have long timeout for the test.
This should deflake the test.

Bug: 937544
Change-Id: I87e0dda7647371e1082639037090264240a5bd06
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1506058
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638458}
diff --git a/service-workers/service-worker/registration-mime-types.https.html b/service-workers/service-worker/registration-mime-types.https.html
index 9ae5f09..1d39ecf 100644
--- a/service-workers/service-worker/registration-mime-types.https.html
+++ b/service-workers/service-worker/registration-mime-types.https.html
@@ -1,5 +1,6 @@
 <!DOCTYPE html>
 <title>Service Worker: Registration (MIME types)</title>
+<meta name=timeout content=long>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="resources/test-helpers.sub.js"></script>