Changed some API names. Wrapped existing UDPClientSocket. Added one unit test...

Changed some API names. Wrapped existing UDPClientSocket. Added one unit test for controller. The socket API itself isn't tested for two reasons: (1) this is an interim checkin, where Part 2 will add UDP receiving, and that will likely involve some API changes, so I didn't bother constructing a whole extension built on a temporary API; and (2) the wrapper itself is so thin around the existing UDPClientSocket API that a unit test of the wrapper wouldn't accomplish much.

BUG=none
TEST=see above.


Review URL: http://codereview.chromium.org/8743017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113069 0039d316-1c4b-4281-b951-d872f2087c98