Cast: Increase UDP socket send buffer size

media/cast/net/cast_transport_sender_impl.h

Index: media/cast/net/cast_transport_sender_impl.h
diff --git a/media/cast/net/cast_transport_sender_impl.h b/media/cast/net/cast_transport_sender_impl.h
index da44e8f21c8d298dc23b2723061388340637ca59..ac3c34e2ad334354fc6ff6ba52777badacf0faa9 100644
--- a/media/cast/net/cast_transport_sender_impl.h
+++ b/media/cast/net/cast_transport_sender_impl.h
@@ -61,6 +61,8 @@ class CastTransportSenderImpl : public CastTransportSender {
   //                                    per 10 ms ideally.
   //   "pacer_max_burst_size": int - specifies how many pakcets to send
   //                                 per 10 ms, max
+  //   "send_buffer_min_size": int - specifies the minimum socket send buffer
+  //                                 size
   //   "disable_wifi_scan" (value ignored) - disable wifi scans while streaming
   //   "media_streaming_mode" (value ignored) - turn media streaming mode on
   // Note, these options may be ignored on some platforms.