The id and src attributes (capped at 500 characters) of the iframe element that holds the
context, or null for the top-level page and workers created by it.
Kind of global scope, such as Window, DedicatedWorkerGlobalScope,
SharedWorkerGlobalScope, ServiceWorkerGlobalScope, or cross-origin-aggregated.
Megabytes attributed to this context.
URL of the frame or worker, capped at 500 characters. Null for cross-origin frames, whose URL the browser does not expose.
Memory held by one frame or worker in a MemoryMeasurement.