net/http: perform streaming body feature detection once per process
As far a I can tell, there's currently no situation where this feature
detection will report a different result per request, so default to
doing once per process until there's evidence that doing it more often
is worthwhile.
Change-Id: I567d3dbd847af2f49f2e83cd9eb0ae61d82c1f83
Reviewed-on: https://go-review.googlesource.com/c/go/+/513459 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Reviewed-by: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>