Zlib-rs is faster than C

Chromium is kind of stuck with zlib because it's the algorithm that's in the standards, but if you're making your own protocol, you can do even better than this by picking a better algorithm. Zstandard is faster and compresses better. LZ4 is much faster, but not quite as small.

Some reading: https://jolynch.github.io/posts/use_fast_data_algorithms/

(As an aside, at my last job container pushes / pulls were in the development critical path for a lot of workflows. It turns out that sha256 and gzip are responsible for a lot of the time spent during container startup. Fortunately, Zstandard is allowed, and blake3 digests will be allowed soon.)

`Content-Encoding: zstd` was added to Chromium a while ago: https://chromestatus.com/feature/6186023867908096

You can still use deflate for compression, but Brotli and Zstd have been available in all modern browsers for quite some time.