Landing Recent QUIC Changes.

Landing Recent QUIC Changes.

Demoting a warning message to DLOG(INFO) due to high frequency.  Will
follow-up with a different CL to log the actual "unusual, we don't think
this should really happen" case at the WARNING level.

Changed the level of a warning message to dlog(info)

Merge internal change: 78113178
https://codereview.chromium.org/665883003/

Fixes two div by zero bugs in QUIC's BBR pacing code that caused server
crashes.

Fixes are in the internal source code.

Merge internal change: 78017204
https://codereview.chromium.org/670533004/

Simplify QuicUnackedPacketMap to expose AddSentPacket, instead of
AddPacket, OnRetransmittedPacket, and SetSent.

Merge internal change: 77986449
https://codereview.chromium.org/640853005/

Making a whole host of QUIC framing errors pre-decryption non-fatal.  If
someone is sending random junk prefixed with a real user's CID it should
not disrupt the connection.

making the QUIC connection resilliant to injected traffic

Merge internal change: 77961885
https://codereview.chromium.org/667573006/

Added helper methods to get/set previous_cached_network_params_.

Merging the following internal change:

Add varz to track accuracy of QUIC bandwidth predictions.

Plan is to use this data to calculate possible impact of using bandwidth
predictions, get an idea of how accurate our predictions are. Intended
varz output is something like:

.../spdy4_over_quic/stk_predicted_bw_accuracy_within_5_mins
.../spdy4_over_quic/stk_predicted_bw_accuracy_within_50_mins
.../spdy4_over_quic/stk_predicted_bw_accuracy_within_500_mins
.../spdy4_over_quic/stk_predicted_bw_accuracy_any_time
.../spdy4_over_quic/max_stk_predicted_bw_accuracy_within_5_mins
.../spdy4_over_quic/max_stk_predicted_bw_accuracy_within_50_mins
.../spdy4_over_quic/max_stk_predicted_bw_accuracy_within_500_mins
.../spdy4_over_quic/max_stk_predicted_bw_accuracy_any_time

Each of these is a map of 20 buckets, covering 10% chunks of the
[0%, 200%] range. For example, a bandwidth estimate from 25 minutes ago,
that turns out to be 125% of the observed bandwidth, will result in the
stk_predicted_bw_accuracy_within_50_mins_histogram{13} bucket being
incremented.

Merge internal change: 77877600
https://codereview.chromium.org/666003002/

Fix test which times out when FLAGS_quic_allow_more_open_streams is
true. Needed to update test to open additional streams to trigger server
close. Internal version of the test does something similar already.

Merge internal change: 77868811
https://codereview.chromium.org/661423005/

Restoring tests incorrectly removed in cr/77591875

Merge internal change: 77791119

Commented out headers_stream->HasBufferedData() call to fix flaky
HandshakeUnblocksFlowControlBlockedHeadersStream unit test.

BUG=423586
https://codereview.chromium.org/662233003/

Replace calls to set.count() with ContainsKey in QUIC.

Merge internal change: 77762867
https://codereview.chromium.org/665823004/

Allow QUIC's BBR TCP sender to pace based on min rtt and add an explicit
PacingRate() method to SendAlgorithmInterface for BBR.

Merge internal change: 77668996
https://codereview.chromium.org/664923003/

Removing QUIC_VERSION_18.
This also lets us remove the code for
 -hard-coded session limits, since those apply to v19 or greater
 -stats tracking % sessions with no flow control
 -the bulk of AdjustErrorForVersion since there's no outstanding
  versions with new errors

 Removing QUIC_VERSION_18.  Not flag protected.

Merge internal change: 77603158
https://codereview.chromium.org/663013003/

Change QUIC's pacing granularity from 5ms to 1ms to match the kernel's
default granularity.

Merge internal change: 77587738
https://codereview.chromium.org/665083004/

R=rch@chromium.org

Committed: https://crrev.com/6afc6f432ffd8920f4ea8d131177499469657f74
Cr-Commit-Position: refs/heads/master@{#300402}

[Ryan Hamilton, 2014-10-20 22:20:49]

lgtm

[ramant (doing other things), 2014-10-20 22:23:07]

The CQ bit was checked by rtenneti@chromium.org

[commit-bot: I haz the power, 2014-10-20 22:24:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/667763003/1

[commit-bot: I haz the power, 2014-10-21 02:15:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-21 03:11:47]

Patchset 1 (id:??) landed as
https://crrev.com/6afc6f432ffd8920f4ea8d131177499469657f74
Cr-Commit-Position: refs/heads/master@{#300402}