MediaSource: canConstructInDedicatedWorker static property

The canConstructInDedicatedWorker static property of the MediaSource interface returns true if MediaSource worker support is implemented, providing a low-latency feature detection mechanism.

If this were not available, the alternative would be a much higher latency approach such as attempting the creation of a MediaSource object from a dedicated worker and transferring the result back to the main thread.

if (MediaSource.canConstructInDedicatedWorker) {
  // MSE is available in workers; let's do this
}