autoAllocateChunkSize property

For byte streams, the developer can set the autoAllocateChunkSize with a positive integer value to turn on the stream's auto-allocation feature. With this is set, the stream implementation will automatically allocate a view buffer of the specified size in ReadableByteStreamController.byobRequest when required.

This must be set to enable zero-copy transfers to be used with a default ReadableStreamDefaultReader. If not set, a default reader will still stream data, but ReadableByteStreamController.byobRequest will always be null and transfers to the consumer must be via the stream's internal queues.