Switch from using internal constraints to use explicit PeerConnectionFactoryInterface::SetOptions to set command line options on new PeerConnections.

BUG=304024
R=fischman@chromium.org, jiayl@chromium.org

Review URL: https://codereview.chromium.org/30983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232702 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232702