Bug 1630320 - in browser_autocomplete_footer.js wait for the tab to load before attempting to retrieve its content. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D72507

browser/extensions/formautofill/test/browser/browser_autocomplete_footer.js

@@ -25,7 +25,8 @@ add_task(async function test_press_enter_on_footer() {
     );
     const prefTabPromise = BrowserTestUtils.waitForNewTab(
       gBrowser,
-      PRIVACY_PREF_URL
+      PRIVACY_PREF_URL,
+      true
     );
     for (let i = 0; i < listItemElems.length; i++) {
       await BrowserTestUtils.synthesizeKey("VK_DOWN", {}, browser);
@@ -59,7 +60,8 @@ add_task(async function test_click_on_footer() {
     )._optionButton;
     const prefTabPromise = BrowserTestUtils.waitForNewTab(
       gBrowser,
-      PRIVACY_PREF_URL
+      PRIVACY_PREF_URL,
+      true
     );
     // Wait for dropdown animation finished to continue mouse synthesizing.
     await sleep(3000);