Use the right interfaces for PerformanceLongTaskTiming (facebook#45526)

Summary:
Pull Request resolved: facebook#45526

Changelog: [internal]

Just using the right interfaces so we can expose them in the global scope and do refinements as necessary using `instanceof`.

Reviewed By: rshest

Differential Revision: D59911144

packages/react-native/src/private/webapis/performance/LongTasks.js

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow strict
+ */
+
+// flowlint unsafe-getters-setters:off
+
+import type {PerformanceEntryJSON} from './PerformanceEntry';
+
+import {PerformanceEntry} from './PerformanceEntry';
+
+export type PerformanceLongTaskTimingJSON = {
+  ...PerformanceEntryJSON,
+  attribution: $ReadOnlyArray<TaskAttributionTiming>,
+  ...
+};
+
+export class TaskAttributionTiming extends PerformanceEntry {}
+
+const EMPTY_ATTRIBUTION: $ReadOnlyArray<TaskAttributionTiming> =
+  Object.preventExtensions([]);
+
+export class PerformanceLongTaskTiming extends PerformanceEntry {
+  get attribution(): $ReadOnlyArray<TaskAttributionTiming> {
+    return EMPTY_ATTRIBUTION;
+  }
+
+  toJSON(): PerformanceLongTaskTimingJSON {
+    return {
+      ...super.toJSON(),
+      attribution: this.attribution,
+    };
+  }
+}

packages/react-native/src/private/webapis/performance/RawPerformanceEntry.js

@@ -14,6 +14,7 @@ import type {
   RawPerformanceEntryType,
 } from './specs/NativePerformanceObserver';
 
+import {PerformanceLongTaskTiming} from './LongTasks';
 import {PerformanceEntry} from './PerformanceEntry';
 import PerformanceEventTiming from './PerformanceEventTiming';
 import {PerformanceMark, PerformanceMeasure} from './UserTiming';
@@ -37,6 +38,13 @@ export function rawToPerformanceEntry(
       processingEnd: entry.processingEnd,
       interactionId: entry.interactionId,
     });
+  } else if (entry.entryType === RawPerformanceEntryTypeValues.LONGTASK) {
+    return new PerformanceLongTaskTiming({
+      name: entry.name,
+      entryType: rawToPerformanceEntryType(entry.entryType),
+      startTime: entry.startTime,
+      duration: entry.duration,
+    });
   } else if (entry.entryType === RawPerformanceEntryTypeValues.MARK) {
     return new PerformanceMark(entry.name, {
       startTime: entry.startTime,