[BackgroundSync Cleanup] Remove power observer

content/child/background_sync/background_sync_type_converters.h

Index: content/child/background_sync/background_sync_type_converters.h
diff --git a/content/child/background_sync/background_sync_type_converters.h b/content/child/background_sync/background_sync_type_converters.h
index 0cf12a1eca0acb3094d6ead418ef855caf08dba5..4152f2bf7bdad338d79ddc77f3c7bcf1e6ec1cd3 100644
--- a/content/child/background_sync/background_sync_type_converters.h
+++ b/content/child/background_sync/background_sync_type_converters.h
@@ -49,23 +49,6 @@ struct CONTENT_EXPORT TypeConverter<content::BackgroundSyncNetworkState,
       blink::WebSyncRegistration::NetworkState input);
 };
 
-// blink::WebSyncRegistration::PowerState <=>
-//     content::BackgroundSyncPowerState
-
-template <>
-struct CONTENT_EXPORT TypeConverter<blink::WebSyncRegistration::PowerState,
-                     content::BackgroundSyncPowerState> {
-  static blink::WebSyncRegistration::PowerState Convert(
-      content::BackgroundSyncPowerState input);
-};
-
-template <>
-struct CONTENT_EXPORT TypeConverter<content::BackgroundSyncPowerState,
-                     blink::WebSyncRegistration::PowerState> {
-  static content::BackgroundSyncPowerState Convert(
-      blink::WebSyncRegistration::PowerState input);
-};
-
 // blink::WebSyncRegistration <=>
 //     content::SyncRegistration