When servers have a lot of data to send and aren't as latency-sensitive,
it makes sense to send large TLS records, so we care about measuring
both packet-sized and full-sized payloads.
Change-Id: Ib0cf5e0f8660f68a98a04fa86b5989d4a485528b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/35344
Reviewed-by: Adam Langley <agl@google.com>