This CL implements a simple send rate controller for STUN packets when sent through UDP sockets. Rate control is done through a global object, which will be given to each p2p udp socket.

Socket before sending packet to the network will check with throttler for current send date. If current rate is exceeding the allowed limit, packet will be dropped.

R=sergeyu@chromium.org, juberti@chromium.org
TBR=brettw@chromium.org
BUG=276800

Review URL: https://codereview.chromium.org/23441012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224532 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224532