I'm testing this but using Rainbows!, Rails 3.2.14, http 1.1 and I don't see any Content-Length header in this point, this thus fails and compression is skipped.

Rainbows! started with the -N options to not insert any default middleware, so my config.ru is:

```ruby
use Rack::ContentLength
use Rack::Chunked
run Myapp::Application
```