Implement `MallocSizeOf` for the internal context of `CompressionStream`
and `DecompressionStream`. This helps remove the `ignore_malloc_size_of`
annotation in the structs `CompressionStream` and `DecompressionStream`
Testing: Existing tests suffice.
Signed-off-by: Kingsley Yung <kingsley@kkoyung.dev>
The patch implements Compression (https://compression.spec.whatwg.org/)
with the compression and decompression provided by the `flate2` crate
(https://crates.io/crates/flate2).
`flate2` supports several different backends, controlled through the
crate's features. By default, it uses `miniz_oxide`
(https://crates.io/crates/miniz_oxide).
`flate2` provides three modules `read`, `write` and `bufread` which work
on instances of the `std::io::Read`, `std::io::Write` and
`std::io::Bufread` traits, respectively. The `write` module is chosen in
the patch since it matches the streaming model in the specification.
Testing: Enable WPT for Compression API, and introduce WPT expectation.
---------
Signed-off-by: Kingsley Yung <kingsley@kkoyung.dev>
