1 files changed, 50 insertions, 0 deletions
diff --git a/browser/base/content/test/performance/browser_startup_hiddenwindow.js b/browser/base/content/test/performance/browser_startup_hiddenwindow.js
new file mode 100644
index 0000000000..7ad611be94
--- /dev/null
+++ b/browser/base/content/test/performance/browser_startup_hiddenwindow.js
@@ -0,0 +1,50 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function () {
+  if (
+    !AppConstants.NIGHTLY_BUILD &&
+    !AppConstants.MOZ_DEV_EDITION &&
+    !AppConstants.DEBUG
+  ) {
+    ok(
+      !("@mozilla.org/test/startuprecorder;1" in Cc),
+      "the startup recorder component shouldn't exist in this non-nightly/non-devedition/" +
+        "non-debug build."
+    );
+    return;
+  }
+
+  let startupRecorder =
+    Cc["@mozilla.org/test/startuprecorder;1"].getService().wrappedJSObject;
+  await startupRecorder.done;
+
+  let extras = Cu.cloneInto(startupRecorder.data.extras, {});
+
+  let phasesExpectations = {
+    "before profile selection": false,
+    "before opening first browser window": false,
+    "before first paint": !Services.prefs.getBoolPref(
+      "toolkit.lazyHiddenWindow"
+    ),
+
+    // Bug 1531854
+    "before handling user events": true,
+    "before becoming idle": true,
+  };
+
+  for (let phase in extras) {
+    if (!(phase in phasesExpectations)) {
+      ok(false, `Startup phase '${phase}' should be specified.`);
+      continue;
+    }
+
+    is(
+      extras[phase].hiddenWindowLoaded,
+      phasesExpectations[phase],
+      `Hidden window loaded at '${phase}': ${phasesExpectations[phase]}`
+    );
+  }
+});