The object model for stuff coming out of the HttpDecoder and going into the HttpEncoder is a little different now.

HttpObject - everything (requests, responses, content) is an HttpObject
HttpRequest - the initial HTTP request.
HttpContent - a content chunk
DefaultFullHttpRequest - an initial HTTP request that also happens to have content (i.e. not chunked)
HttpResponse - the initial HTTP response
DefaultFullHttpResponse - an initial HTTP response that also happens to have content (i.e. not chunked)