Bugzilla

I have a [Glean event](https://searchfox.org/mozilla-central/rev/aec3a901e6f6b3041b5ec457c9111a042cef1fb1/browser/components/metrics.yaml#13-40) mirrored to a [legacy telemetry event](https://searchfox.org/mozilla-central/rev/aec3a901e6f6b3041b5ec457c9111a042cef1fb1/toolkit/components/telemetry/Events.yaml#1047-1069).  The event is only emitted in [a single place](https://searchfox.org/mozilla-central/rev/aec3a901e6f6b3041b5ec457c9111a042cef1fb1/browser/components/BrowserContentHandler.sys.mjs#1043).

When I query for event counts, I get 3x as many legacy events: compare [Glean](https://sql.telemetry.mozilla.org/queries/90242/source?p_channel=release&p_date=d_last_14_days&p_version=113) with ~500 events for `backgroundtaskmessage-notification-release-4pct-en:treatment-old` to [legacy](https://sql.telemetry.mozilla.org/queries/92527/source?p_channel=release&p_date=d_last_14_days&p_version=113) with ~1500 events for `backgroundtaskmessage-notification-release-4pct-en:treatment-old`.

I have a [Glean event](https://searchfox.org/mozilla-central/rev/aec3a901e6f6b3041b5ec457c9111a042cef1fb1/browser/components/metrics.yaml#13-40) mirrored to a [legacy telemetry event](https://searchfox.org/mozilla-central/rev/aec3a901e6f6b3041b5ec457c9111a042cef1fb1/toolkit/components/telemetry/Events.yaml#1047-1069).  The event is only emitted in [a single place](https://searchfox.org/mozilla-central/rev/aec3a901e6f6b3041b5ec457c9111a042cef1fb1/browser/components/BrowserContentHandler.sys.mjs#1043).

When I query for event counts, I get 3x as many legacy events: compare [Glean](https://sql.telemetry.mozilla.org/queries/90242/source?p_channel=release&p_date=2023-05-23--2023-06-07&p_version=113) with ~500 events for `backgroundtaskmessage-notification-release-4pct-en:treatment-old` to [legacy](https://sql.telemetry.mozilla.org/queries/92527/source?p_channel=release&p_date=2023-05-23--2023-06-07&p_version=113) with ~1500 events for `backgroundtaskmessage-notification-release-4pct-en:treatment-old`.