Land Recent QUIC Changes until 03/02/2015.

Land Recent QUIC Changes until 03/02/2015.

CL generated with data from dead-code analysis using
.../scythe:remove_dead_code #codehealth

Merge internal change: 87564533
https://codereview.chromium.org/973683003/

Change QUIC's PrrSender::TimeUntilSend to accept bytes instead of
packets.  No functional change.

Merge internal change: 87535917
https://codereview.chromium.org/972033002/

Discard acks from QUIC's UnackedPacketMap when the map is larger than
one half of its max size(2500).  Was previously 200.

Merge internal change: 87419283
https://codereview.chromium.org/977453002/

Remove TCP and BBR's max congestion window.  No practical change,
because Chrome's receive window is the limiting factor.

Adds kMaxReportedCwnd and kMaxReorderingForRtt as constants to replace
the max CWND in classes that used to rely on max CWND.

Merge internal change: 87346681
https://codereview.chromium.org/968923005/

Minor simplification to QuicSentPacketManager::PendingRetransmission.
No functional change.

Merge internal change: 87254408
https://codereview.chromium.org/969153002/

Log the QUIC SRBF (socket receive buffer size) as an int instead of
hex value.

Merge internal change: 87247898
https://codereview.chromium.org/974593002/

Minimally test a few things to keep them from Scythe. test-only change.

Merge internal change: 87171236
https://codereview.chromium.org/971493003/

Deprecate FLAGS_quic_limit_time_wait_list_size.

Merge internal change: 87059868
https://codereview.chromium.org/968323002/

CL generated with data from dead-code analysis using
.../scythe:remove_dead_code #codehealth

Merge internal change: 86999211
https://codereview.chromium.org/974563002/

Remove unused ability to disable flow control in QUIC

QuicFlowController::Disable() is no longer called. It was used when we
disabled flow control for the headers and crypto streams, and for old
versions which did not support connection level flow control. Now that
we are on QUIC_VERSION_23, we now use flow control on all streams and
all connections, so this is safe to remove.

Thanks to tgreer@ for the scythe code removal in cl/86835556, and
alyssar@ for noticing that the removal of the dead
QuicFlowController:Disable() meant we could remove substantially more in
this CL.

Merge internal change: 86960342
https://codereview.chromium.org/969053004/

Remove unnecessary virtual CreateQuicConnection method.

Merge internal change: 86947282
https://codereview.chromium.org/972783002/

R=rch@chromium.org

Committed: https://crrev.com/ae5ac43d4e570358d18b94e9007283078ee7c456
Cr-Commit-Position: refs/heads/master@{#318846}

[Ryan Hamilton, 2015-03-03 05:11:38]

lgtm

[ramant (doing other things), 2015-03-03 05:41:19]

The CQ bit was checked by rtenneti@chromium.org

[commit-bot: I haz the power, 2015-03-03 05:42:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/968233004/1

[commit-bot: I haz the power, 2015-03-03 06:37:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-03 06:37:49]

Patchset 1 (id:??) landed as
https://crrev.com/ae5ac43d4e570358d18b94e9007283078ee7c456
Cr-Commit-Position: refs/heads/master@{#318846}