Bug 1541248 - Make sure browser_storage_values.js does not depend on the value of the privacy.documentCookies.maxage pref; r=baku on a CLOSED TREE

Differential Revision: https://phabricator.services.mozilla.com/D25878

--HG--
extra : source : cc704998fa1500bc170cba068d1731aab64057c7
extra : histedit_source : 033596cba01318aad1a61454d9ad1d4b7b64f87b

devtools/client/storage/test/browser_storage_values.js

@@ -149,6 +149,8 @@ const testCases = [
 ];
 
 add_task(async function() {
+  await SpecialPowers.pushPrefEnv({set: [["privacy.documentCookies.maxage", 0]]});
+
   await openTabAndSetupStorage(MAIN_DOMAIN + "storage-complex-values.html");
 
   gUI.tree.expandAll();