Revert of Enable HTTP/2 to use a LIFO scheduler to schedule write. (patchset #1 id:1 of https://codereview.chromium.org/2844963005/ )

Reason for revert:
Reverting in hopes of fixing net_unittests. Specifically NSS/ClientCertStoreTest/0.CertAuthorityFiltering . See 716630.

Original issue's description:
> Enable HTTP/2 to use a LIFO scheduler to schedule write.
>
> This CL lands server change 152524616 by yasong.
>
> BUG=488484
>
> Review-Url: https://codereview.chromium.org/2844963005
> Cr-Commit-Position: refs/heads/master@{#467971}
> Committed: https://chromium.googlesource.com/chromium/src/+/c443c00c0c9e10b8ced1064d7da18c3a9668cac2

TBR=bnc@chromium.org,yasong@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=488484

Review-Url: https://codereview.chromium.org/2849983002
Cr-Original-Commit-Position: refs/heads/master@{#468165}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: bc96e065ec4ed456aa427e5a3492c01e20f70dcf
2 files changed