Revert of Landing Recent QUIC Changes.

Revert of Landing Recent QUIC Changes. (patchset #1 id:1 of https://codereview.chromium.org/903013002/)

Reason for revert:
Broke the build

Original issue's description:
> Landing Recent QUIC Changes.
>
> Making the (deprecation-in-progress) congestion field write only.
>
> This is a bit of a hack because technically it's "required" for
> QUIC_VERSION_23 but as all the internal servers and all of chrome builds
> picking up this change consider the field optional despite the version,
> it should just Work (TM).
>
> I was hoping to stop sending the congestion fields for v24 clients but
> that is not safe until the internal server fleet doesn't consider it a
> required field for negotiated()=true.  Bah.
>
> No longer reading the (deprecated) congestion fields for QUIC.
>
> Merge internal change: 85158634
> https://codereview.chromium.org/898233003/
>
> Improving junk packet handling for QUIC by ignoring packets with client
> port 0.
>
> Merge internal change: 85067984
> https://codereview.chromium.org/885713009/
>
> Removing deprecated flag FLAGS_quic_use_initial_rtt_for_stats.
>
> Merge internal change: 84999682
> https://codereview.chromium.org/883393008/
>
> Adding more error logging for failed QUIC writes.
>
> Merge internal change: 84989992
> https://codereview.chromium.org/898243002/
>
> Further cleanup to QuicAckNotifier and QuicAckNotifierManager.
> No functional change.
>
> Merge internal change: 84784925
> https://codereview.chromium.org/880403006/
>
> Remove an unneeded hash_set from QuicAckNotifierManager.
> No change in behavior.
>
> Merge internal change: 84637544
> https://codereview.chromium.org/872403007/
>
> Minor cleanup and optimization of QuicConnection::IsConnectionClose.
>
> Merge internal change: 84624803
> https://codereview.chromium.org/903973002/
>
> Rename QuicAckNotifier's AddSequenceNumber to OnSerializedPacket.
> No functional change.
>
> Merge internal change: 84624660
> https://codereview.chromium.org/867293004/
>
> R=rch@chromium.org
>
> Committed: https://crrev.com/ff331b65e0aef293ed6f1d0954b83ae17cc66d28
> Cr-Commit-Position: refs/heads/master@{#315086}

TBR=rch@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/d4f719623ae9a736e09f5bb259f44d147b998613
Cr-Commit-Position: refs/heads/master@{#315091}

[ramant (doing other things), 2015-02-06 20:02:54]

Created Revert of Landing Recent QUIC Changes.

[commit-bot: I haz the power, 2015-02-06 20:04:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/908623002/1

[commit-bot: I haz the power, 2015-02-06 20:05:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-06 20:05:57]

Patchset 1 (id:??) landed as
https://crrev.com/d4f719623ae9a736e09f5bb259f44d147b998613
Cr-Commit-Position: refs/heads/master@{#315091}