Bug 1598629 - Part 2: Re-enable disable start button mochitest r=jdescottes

Differential Revision: https://phabricator.services.mozilla.com/D54964

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

devtools/client/application/test/browser/browser.ini

@@ -30,7 +30,7 @@ support-files =
 [browser_application_panel_debug-service-worker.js]
 skip-if = debug || asan # Bug 1559591, 1575578
 [browser_application_panel_disable-start-service-worker.js]
-skip-if = (os == 'linux' && asan) || debug || serviceworker_e10s # Bug 1559487, 1559591, 1447197
+skip-if = (os == 'linux' && asan) || debug # Bug 1559487, 1559591
 [browser_application_panel_list-domain-workers.js]
 skip-if = debug # Bug 1559591
 [browser_application_panel_list-several-workers.js]
@@ -49,4 +49,4 @@ skip-if = true # Bug 1467256, 1559591
 [browser_application_panel_unregister-worker.js]
 skip-if = debug # Bug 1559591
 [browser_application_panel_start-service-worker.js]
-skip-if = (os == 'linux' && asan) || debug # Bug 1559487, 1559591, 1447197
+skip-if = (os == 'linux' && asan) || debug # Bug 1559487, 1559591

devtools/client/application/test/browser/browser_application_panel_disable-start-service-worker.js

@@ -11,9 +11,19 @@ const TAB_URL = URL_ROOT + "resources/service-workers/simple.html";
 add_task(async function() {
   await enableApplicationPanel();
 
-  // disable sw debugging by increasing the # of processes and thus multi-e10s kicking in
+  // Setting a low idle_timeout and idle_extended_timeout will allow the service worker
+  // to reach the STOPPED state quickly, which will allow us to test the start button.
+  // The default value is 30000 milliseconds.
+  info("Set a low service worker idle timeout");
+  await pushPref("dom.serviceWorkers.idle_timeout", 1000);
+  await pushPref("dom.serviceWorkers.idle_extended_timeout", 1000);
+
+  // disable sw debugging
   info("Disable service worker debugging");
-  await pushPref("dom.ipc.processCount", 8);
+  await pushPref(
+    "devtools.debugger.features.windowless-service-workers",
+    false
+  );
 
   const { panel, tab, target } = await openNewTabAndApplicationPanel(TAB_URL);
   const doc = panel.panelWin.document;