Overlap between StreamReader and FileReader

StreamReader proposed in the Streams API spec is almost the same as
FileReader. By adding the maxSize argument to the readAs methods (new
methods or just add it to existing methods as an optional argument) and
adding the readAsBlob method, FileReader can cover all what StreamReader
provides. Has this already been discussed here?

I heard that some people who had this concern discussed briefly and were
worrying about derailing File API standardization.

We're planning to implement it on Chromium/Blink shortly.