Bug 1894554 - Forcefully trigger TelemetryControllers delayed initialization when opening about:telemetry. r=chutten

Differential Revision: https://phabricator.services.mozilla.com/D209165

toolkit/components/telemetry/app/TelemetryControllerParent.sys.mjs

@@ -256,6 +256,15 @@ export var TelemetryController = Object.freeze({
   promiseInitialized() {
     return Impl.promiseInitialized();
   },
+
+  /**
+   * Allows to trigger TelemetryControllers delayed initialization now and waiting for its completion.
+   * The returned promise is guaranteed to resolve before TelemetryController is shutting down.
+   * @return {Promise} Resolved when delayed TelemetryController initialization completed.
+   */
+  ensureInitialized() {
+    return Impl.ensureInitialized();
+  },
 });
 
 var Impl = {
@@ -1158,6 +1167,18 @@ var Impl = {
     return this._delayedInitTaskDeferred.promise;
   },
 
+  /**
+   * Allows to trigger TelemetryControllers delayed initialization now and waiting for its completion.
+   * This will complete before TelemetryController is shutting down.
+   * @return {Promise} Resolved when delayed TelemetryController initialization completed.
+   */
+  ensureInitialized() {
+    if (this._delayedInitTask) {
+      return this._delayedInitTask.finalize();
+    }
+    return Promise.resolve();
+  },
+
   getCurrentPingData(aSubsession) {
     this._log.trace("getCurrentPingData - subsession: " + aSubsession);
 

toolkit/content/aboutTelemetry.js

@@ -352,6 +352,12 @@ var PingPicker = {
   },
 
   _updateCurrentPingData() {
+    TelemetryController.ensureInitialized().then(() =>
+      this._doUpdateCurrentPingData()
+    );
+  },
+
+  _doUpdateCurrentPingData() {
     const subsession = document.getElementById("show-subsession-data").checked;
     let ping = TelemetryController.getCurrentPingData(subsession);
     if (!ping) {