1 files changed, 55 insertions, 0 deletions
diff --git a/browser/base/content/test/performance/StartupContentSubframe.sys.mjs b/browser/base/content/test/performance/StartupContentSubframe.sys.mjs
new file mode 100644
index 0000000000..a78e456afb
--- /dev/null
+++ b/browser/base/content/test/performance/StartupContentSubframe.sys.mjs
@@ -0,0 +1,55 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * test helper JSWindowActors used by the browser_startup_content_subframe.js test.
+ */
+
+export class StartupContentSubframeParent extends JSWindowActorParent {
+  receiveMessage(msg) {
+    // Tell the test about the data we received from the content process.
+    Services.obs.notifyObservers(
+      msg.data,
+      "startup-content-subframe-loaded-scripts"
+    );
+  }
+}
+
+export class StartupContentSubframeChild extends JSWindowActorChild {
+  async handleEvent(event) {
+    // When the remote subframe is loaded, an event will be fired to this actor,
+    // which will cause us to send the `LoadedScripts` message to the parent
+    // process.
+    // Wait a spin of the event loop before doing so to ensure we don't
+    // miss any scripts loaded immediately after the load event.
+    await new Promise(resolve => Services.tm.dispatchToMainThread(resolve));
+
+    const Cm = Components.manager;
+    Cm.QueryInterface(Ci.nsIServiceManager);
+    const { AppConstants } = ChromeUtils.importESModule(
+      "resource://gre/modules/AppConstants.sys.mjs"
+    );
+    let collectStacks = AppConstants.NIGHTLY_BUILD || AppConstants.DEBUG;
+
+    let modules = {};
+    for (let module of Cu.loadedJSModules) {
+      modules[module] = collectStacks ? Cu.getModuleImportStack(module) : "";
+    }
+    for (let module of Cu.loadedESModules) {
+      modules[module] = collectStacks ? Cu.getModuleImportStack(module) : "";
+    }
+
+    let services = {};
+    for (let contractID of Object.keys(Cc)) {
+      try {
+        if (Cm.isServiceInstantiatedByContractID(contractID, Ci.nsISupports)) {
+          services[contractID] = "";
+        }
+      } catch (e) {}
+    }
+    this.sendAsyncMessage("LoadedScripts", {
+      modules,
+      services,
+    });
+  }
+}