Bug 1589102 - Part 5: Fix tests that relied on about:blank loads happening instantenously, r=mattwoodrow

Differential Revision: https://phabricator.services.mozilla.com/D85083

devtools/client/webconsole/test/browser/browser_webconsole_multiple_windows_and_tabs.js

@@ -23,10 +23,9 @@ add_task(async function() {
   info("Test tabs added in first window");
 
   info("Open a second window");
+  const windowOpenedPromise = BrowserTestUtils.waitForNewWindow();
   const win2 = OpenBrowserWindow();
-  await new Promise(r => {
-    win2.addEventListener("load", r, { capture: true, once: true });
-  });
+  await windowOpenedPromise;
 
   info("Add test tabs in second window");
   const tab3 = await addTab(TEST_URI, { window: win2 });

docshell/test/navigation/file_scrollRestoration.html

@@ -55,8 +55,9 @@
           case 5: {
             opener.isnot(Math.round(window.scrollY), 0, "Should have scrolled to #hash.");
             opener.is(history.scrollRestoration, "manual", "Should have the same scrollRestoration mode as before fragment navigation.");
-            window.onunload = function() {}; // Disable bfcache.
-            opener.setTimeout("is(SpecialPowers.wrap(testWindow).history.scrollRestoration, 'auto'); SpecialPowers.wrap(testWindow).history.back();", 250);
+            window.onunload = function() {
+              opener.setTimeout("is(SpecialPowers.wrap(testWindow).history.scrollRestoration, 'auto'); SpecialPowers.wrap(testWindow).history.back();", 250);
+            }; // Disable bfcache.
             window.location.href = "about:blank";
             break;
           }

docshell/test/navigation/test_bug386782.html

@@ -70,7 +70,10 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=386782
       is(gTest.window.document.body.innerHTML, gTest.expectedBodyAfterEdit, "Editing failed.");
 
       gTest.window.location = "about:blank";
-      SimpleTest.waitForFocus(goBack, gTest.window);
+      let cond = () => gTest.window.location.href == "about:blank";
+      SimpleTest.waitForCondition(cond, () => {
+        SimpleTest.waitForFocus(goBack, gTest.window, true);
+      }, "about:blank never loaded");
     }
 
     function goBack() {