Bug 1613645 - wait for translation before checking strings in urlbar interventions tests. r=adw

Differential Revision: https://phabricator.services.mozilla.com/D61831

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

browser/components/urlbar/tests/browser/head.js

@@ -103,6 +103,7 @@ async function checkIntervention({
   // Do a search that triggers the tip.
   let [result, element] = await awaitTip(searchString);
   Assert.strictEqual(result.payload.type, tip);
+  await element.ownerDocument.l10n.translateFragment(element);
 
   let actualTitle = element._elements.get("title").textContent;
   if (typeof title == "string") {

browser/components/urlbar/tests/browser/interventions_update/head.js

@@ -230,8 +230,8 @@ async function doUpdateTest({
 } = {}) {
   // Do a search that triggers the tip.
   let [result, element] = await awaitTip(searchString);
-
   Assert.strictEqual(result.payload.type, tip, "Tip type");
+  await element.ownerDocument.l10n.translateFragment(element);
 
   let actualTitle = element._elements.get("title").textContent;
   if (typeof title == "string") {