Mark ResourceTiming idlharness test as long

Bug: 1065535
Change-Id: Ie708216490b17d03319c5224bbe466cf0b0937d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2127730
Commit-Queue: Nicolás Peña Moreno <npm@chromium.org>
Commit-Queue: Yoav Weiss <yoavweiss@chromium.org>
Auto-Submit: Nicolás Peña Moreno <npm@chromium.org>
Reviewed-by: Yoav Weiss <yoavweiss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754567}

third_party/blink/web_tests/external/wpt/resource-timing/idlharness.any.js

 // META: script=/resources/WebIDLParser.js
 // META: script=/resources/idlharness.js
+// META: timeout=long
 
 'use strict';