Bug 1842646 - Add telemetry for always offer translations r=gregtatum

Adds a new telemetry event that corresponds to toggling
the always-offer-translations settings menu item in the
Translations panel.

Differential Revision: https://phabricator.services.mozilla.com/D186252

browser/components/translations/content/translationsPanel.js

@@ -1362,7 +1362,8 @@ var TranslationsPanel = new (class {
    * Toggle offering translations.
    */
   async onAlwaysOfferTranslations() {
-    TranslationsParent.toggleAutomaticallyPopupPref();
+    const toggledOn = TranslationsParent.toggleAutomaticallyPopupPref();
+    TranslationsParent.telemetry().panel().onAlwaysOfferTranslations(toggledOn);
   }
 
   /**

toolkit/components/translations/TranslationsTelemetry.sys.mjs

@@ -307,6 +307,17 @@ class Panel {
     TranslationsTelemetry.logEventToConsole("onTranslateButton");
   }
 
+  static onAlwaysOfferTranslations(toggledOn) {
+    Glean.translationsPanel.alwaysOfferTranslations.record({
+      flow_id: TranslationsTelemetry.getOrCreateFlowId(),
+      first_interaction: Panel.isFirstUserInteraction(),
+      toggled_on: toggledOn,
+    });
+    TranslationsTelemetry.logEventToConsole(
+      `[${toggledOn ? "✔" : "x"}] onAlwaysOfferTranslations`
+    );
+  }
+
   static onAlwaysTranslateLanguage(langTag, toggledOn) {
     Glean.translationsPanel.alwaysTranslateLanguage.record({
       flow_id: TranslationsTelemetry.getOrCreateFlowId(),

toolkit/components/translations/actors/TranslationsParent.sys.mjs

@@ -2248,12 +2248,18 @@ export class TranslationsParent extends JSWindowActorParent {
   /**
    * Toggle the automatically popup pref, which will either
    * enable or disable translations being offered to the user.
+   *
+   * @returns {boolean}
+   *  True if offering translations was enabled by this call.
+   *  False if offering translations was disabled by this call.
    */
   static toggleAutomaticallyPopupPref() {
+    const prefValueBeforeToggle = lazy.automaticallyPopupPref;
     Services.prefs.setBoolPref(
       "browser.translations.automaticallyPopup",
-      !lazy.automaticallyPopupPref
+      !prefValueBeforeToggle
     );
+    return !prefValueBeforeToggle;
   }
 
   /**

toolkit/components/translations/metrics.yaml

@@ -410,6 +410,27 @@ translations.panel:
       - translations-telemetry-alerts@mozilla.com
     expires: 122
 
+  always_offer_translations:
+    type: event
+    description: >
+      Triggers when the always-offer-translations menuitem is invoked in the translations panel seeings.
+    extra_keys:
+      flow_id: *flow_id
+      first_interaction: *first_interaction
+      toggled_on:
+        type: boolean
+        description: >
+          - Whether the setting was toggled on or off.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1842646
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1842646
+    data_sensitivity:
+      - interaction
+    notification_emails:
+      - translations-telemetry-alerts@mozilla.com
+    expires: 122
+
   always_translate_language:
     type: event
     description: >