Create and use a seeded random number generator
(PortSuggester) to suggest what ephemeral source port
should be used when opening a UDP client socket in QUIC.

This should increase the likelihood of 0-RTT connections, even if a strike server is not used across a server cluster.

BUG=326545

Review URL: https://codereview.chromium.org/107803002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239426 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239426