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

jingle/glue/proxy_resolving_client_socket.cc

Index: jingle/glue/proxy_resolving_client_socket.cc
diff --git a/jingle/glue/proxy_resolving_client_socket.cc b/jingle/glue/proxy_resolving_client_socket.cc
index 1a420f564b701587286790a701e4d5422c033d26..278a3b3775b8f8a93f0aed636a714545069048be 100644
--- a/jingle/glue/proxy_resolving_client_socket.cc
+++ b/jingle/glue/proxy_resolving_client_socket.cc
@@ -133,6 +133,13 @@ int ProxyResolvingClientSocket::SetSendBufferSize(int32_t size) {
   return net::ERR_SOCKET_NOT_CONNECTED;
 }
 
+int ProxyResolvingClientSocket::SetDoNotFragment(bool do_not_fragment) {
+  if (transport_.get() && transport_->socket())
+    return transport_->socket()->SetSendBufferSize(do_not_fragment);
+  NOTREACHED();
+  return net::ERR_SOCKET_NOT_CONNECTED;
+}
+
 int ProxyResolvingClientSocket::Connect(
     const net::CompletionCallback& callback) {
   DCHECK(user_connect_callback_.is_null());