Bug 1569420 - Use scheme parameter instead of hardcoded "http" r=mconley

Differential Revision: https://phabricator.services.mozilla.com/D39608

--HG--
extra : moz-landing-system : lando

browser/components/sessionstore/test/browser_cookies_privacy.js

@@ -4,7 +4,7 @@
 const MAX_EXPIRY = Math.pow(2, 62);
 
 function addCookie(scheme, secure = false) {
-  let cookie = createTestCookie("http", secure);
+  let cookie = createTestCookie(scheme, secure);
   Services.cookies.add(
     cookie.host,
     cookie.path,