Bug 1499474 - Check if the element has textContent before falling back to TestUtils.waitForCondition. r=MattN

This patch reduced the time to run from 2 minutes to 15 seconds.

Differential Revision: https://phabricator.services.mozilla.com/D8895

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

browser/extensions/formautofill/test/browser/browser_editAddressDialog.js

@@ -324,8 +324,11 @@ add_task(async function test_countryFieldLabels() {
 
       // Check that the labels were filled
       for (let labelEl of mutatableLabels) {
-        await TestUtils.waitForCondition(() => labelEl.textContent,
-                                         "Wait for label to be populated by the mutation observer");
+        if (!labelEl.textContent) {
+          await TestUtils.waitForCondition(() => labelEl.textContent,
+                                           "Wait for label to be populated by the mutation observer",
+                                           10);
+        }
         isnot(labelEl.textContent, "",
               "Ensure textContent is non-empty for: " + countryOption.value);
         is(labelEl.dataset.localization, undefined,