Add a SetDoNotFragment() method to DatagramSocket, and call this for

net/socket/socks_client_socket.cc

Index: net/socket/socks_client_socket.cc
diff --git a/net/socket/socks_client_socket.cc b/net/socket/socks_client_socket.cc
index b5d5ce02e109df83df93775bd0c938aac81f3767..042faf43fb9eb8802f8c329d85acae97feaf790c 100644
--- a/net/socket/socks_client_socket.cc
+++ b/net/socket/socks_client_socket.cc
@@ -218,6 +218,10 @@ int SOCKSClientSocket::SetSendBufferSize(int32_t size) {
   return transport_->socket()->SetSendBufferSize(size);
 }
 
+int SOCKSClientSocket::SetDoNotFragment(bool do_not_fragment) {
+  return transport_->socket()->SetDoNotFragment(do_not_fragment);
+}
+
 void SOCKSClientSocket::DoCallback(int result) {
   DCHECK_NE(ERR_IO_PENDING, result);
   DCHECK(!user_callback_.is_null());