GitLab

* Update hugely out-of-date comment for SpdySession::GetPushedStream().
* Drop unused |stream_net_log| argument.
* Do not reset |*stream| upon error.  The only production call site is
  in SpdyHttpStream::InitializeStream(), where |stream_| is already
  guaranteed to be nullptr when GetPushedStream() is called, see DCHECK
  in line 139.

Change-Id: I4b7b5738dd171df9f01fc1bfd7ddec8376985e08
Reviewed-on: https://chromium-review.googlesource.com/c/1257442Reviewed-by: Nick Harper <nharper@chromium.org>
Commit-Queue: Bence Béky <bnc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596074}