Bug 1923028 - Migrate scalars to use Glean APIs for preferences.prefs_file_was_invalid, r=chutten.

Differential Revision: https://phabricator.services.mozilla.com/D225373

modules/libpref/Preferences.cpp

@@ -42,7 +42,6 @@
 #include "mozilla/StaticPrefsAll.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/SyncRunnable.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/Try.h"
 #include "mozilla/UniquePtrExtensions.h"
 #include "mozilla/URLPreloader.h"
@@ -4376,8 +4375,7 @@ already_AddRefed<nsIFile> Preferences::ReadSavedPrefs() {
       // Save a backup copy of the current (invalid) prefs file, since all prefs
       // from the error line to the end of the file will be lost (bug 361102).
       // TODO we should notify the user about it (bug 523725).
-      Telemetry::ScalarSet(
-          Telemetry::ScalarID::PREFERENCES_PREFS_FILE_WAS_INVALID, true);
+      glean::preferences::prefs_file_was_invalid.Set(true);
       MakeBackupPrefFile(file);
     }
   }

modules/libpref/metrics.yaml

@@ -38,3 +38,21 @@ security:
           The name of the pref.
         type: string
     telemetry_mirror: Security_Prefusage_Contentprocess
+
+preferences:
+  prefs_file_was_invalid:
+    type: boolean
+    description: >
+      Set to true if a failure occurred reading profile/prefs.js.
+      This metric was generated to correspond to the Legacy Telemetry
+      scalar preferences.prefs_file_was_invalid.
+    bugs:
+      - https://bugzil.la/1367813
+      - https://bugzil.la/1682571
+    data_reviews:
+      - https://bugzil.la/1367813
+      - https://bugzil.la/1682571
+    notification_emails:
+      - kwright@mozilla.com
+    expires: never
+    telemetry_mirror: PREFERENCES_PREFS_FILE_WAS_INVALID