Bug 1715264 - Fix browser_async_flushes.js for SHIP, r=farre

Relies on frame script message ordering.

Differential Revision: https://phabricator.services.mozilla.com/D117232

browser/components/sessionstore/test/browser.ini

@@ -84,9 +84,7 @@ support-files = file_async_duplicate_tab.html
 support-files = file_async_flushes.html
 run-if = e10s && crashreporter
 skip-if =
-  debug # bug 1167933
   apple_silicon  # crash
-  fission && (os != "linux" || asan)  # Bug 1713900 - new Fission platform triage
 [browser_async_remove_tab.js]
 run-if = e10s
 skip-if =

browser/components/sessionstore/test/browser_async_flushes.js

@@ -45,6 +45,14 @@ add_task(async function test_flush() {
 });
 
 add_task(async function test_crash() {
+  if (Services.appinfo.sessionHistoryInParent) {
+    // This test relies on frame script message ordering. Since the frame script
+    // is unused with SHIP, there's no guarantee that we'll crash the frame
+    // before we've started the flush.
+    ok(true, "Test relies on frame script message ordering.");
+    return;
+  }
+
   // Create new tab.
   let tab = BrowserTestUtils.addTab(gBrowser, URL);
   gBrowser.selectedTab = tab;