net/http: document when request bodies are closed in more places
It isn't obvious that request bodies can be closed asynchronously,
and it's easy to overlook the documentation of this fact in
RoundTripper, which is a fairly low-level interface.
Change-Id: I3b825c505418af7e1d3f6ed58f3704e55cf16901
Reviewed-on: https://go-review.googlesource.com/c/go/+/523036
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Damien Neil <dneil@google.com> Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Damien Neil <dneil@google.com>