Land Recent QUIC Changes.

QUIC - manually sync'ing changes between chrome and internal source
code.

Refactorings to QuicCryptoServerConfig to allow for async quic client
hello validation.

Merge internal change: 56375103

- Remove the QuicConnectionPeer::GetCongestionManager method (can call
  QuicConnection()::congestion_manager() directly now).
- Update a bunch of CongestionManager/SendAlgorithm methods to be const.

Merge internal change: 56361306

Change the QuicDispatcher to immediately put packets in time wait when
there is no version negotiation packet, instead of creating a new
session.

Merge internal change: 56353674

Add a new PacingSender which can be used to add pacing on top of an
existing QUIC sender.

Merge internal change: 56183480

Move StrikeRegisterClient to gfe/quic/crypto, so that
QuicCryptoServerConfig can depend on it. Implement a
StrikeRegisterClient that queries a local StrikeRegister.

See internal CL 56173502 for use cases.

Merge internal change: 56316281

R=rch@chromium.org

Review URL: https://codereview.chromium.org/75163007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235976 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235976