Bug 1608353 - Wait for requests to settle in browser_about_debugging_link.js r=rpl

Differential Revision: https://phabricator.services.mozilla.com/D64861

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

toolkit/mozapps/extensions/test/browser/browser_about_debugging_link.js

@@ -101,6 +101,7 @@ add_task(async function testAboutDebugging() {
   );
   debugAddonsBtn.click();
   await switched;
+  await waitForRequestsToSettle(AboutDebugging.store);
 
   info("Force about:debugging to a different hash URL");
   aboutDebuggingTab.linkedBrowser.contentWindow.location.hash = "/setup";
@@ -115,6 +116,7 @@ add_task(async function testAboutDebugging() {
   );
   debugAddonsBtn.click();
   await switched;
+  await waitForRequestsToSettle(AboutDebugging.store);
 
   info("Wait until any new about:debugging request did settle");
   // Avoid test failures due to closing the about:debugging tab