[fetch] Support full-duplex HTTP streaming (#229)

I’d like to ask that Fetch API explicitly supports full-duplex HTTP streaming. The API structure already logically allows for this, with the only missing component being request streams, which I understand are coming eventually. This was discussed [informally before][1] and has been [proposed to the IETF][2] in a form that is now [explicitly supported by the HTTP2 specification][3] (“A server can send a complete response prior to the client sending an entire request if the response does not depend on any portion of the request that has not been sent and received”). 

If there are ecosystem concerns this behavior could be confined to HTTP2 transports only. I believe a number of proxies support this behavior today and when TLS is used would be oblivious to it anyway. I know a number of HTTP2 implementations already support this (nghttp2, Google) and there are probably others

This would give service implementers a clear roadmap for full duplex streaming in the browser over HTTP2 without waiting for [draft-hirano-httpbis-websocket-over-http2][4] to come back from the dead.

[1]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=23992#c2
[2]: https://tools.ietf.org/html/draft-zhu-http-fullduplex-02  
[3]: https://tools.ietf.org/html/rfc7540#section-8.1
[4]: https://tools.ietf.org/html/draft-hirano-httpbis-websocket-over-http2-01


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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/issues/229