Method for streaming data from browser to server via HTTP

Are there any XHR-like browser APIs available for streaming binary to a server over HTTP?

I want to make an HTTP PUT request and create data programmatically, over time. I don't want to create all this data at once, since there could be gigs of it sitting in memory. Some psueudo-code to illustrate what I'm getting at:

var dataGenerator = new DataGenerator(); // Generates 8KB UInt8Array every second
var streamToWriteTo;
http.put('/example', function (requestStream) {
  streamToWriteTo = requestStream;
});

dataGenerator.on('data', function (chunk) {
  if (!streamToWriteTo) {
    return;
  }
  streamToWriteTo.write(chunk);
});

I currently have a web socket solution in place instead, but would prefer regular HTTP for better interop with some existing server-side code.

EDIT: I can use bleeding edge browser APIs. I was looking at the Fetch API, as it supports ArrayBuffers, DataViews, Files, and such for request bodies. If I could somehow fake out one of these objects so that I could use the Fetch API with dynamic data, that would work for me. I tried creating a Proxy object to see if any methods were called that I could monkey patch. Unfortunately, it seems that the browser (at least in Chrome) is doing the reading in native code and not in JS land. But, please correct me if I'm wrong on that.