Cast: Let the extension control if DSCP is on or off.

chrome/renderer/media/cast_transport_sender_ipc.cc

Index: chrome/renderer/media/cast_transport_sender_ipc.cc
diff --git a/chrome/renderer/media/cast_transport_sender_ipc.cc b/chrome/renderer/media/cast_transport_sender_ipc.cc
index d2624d6c4f7422cff1f54ffff9e9e36b8539d36e..4f438978c37b70f4ffc718097ad22908a2eea652 100644
--- a/chrome/renderer/media/cast_transport_sender_ipc.cc
+++ b/chrome/renderer/media/cast_transport_sender_ipc.cc
@@ -16,13 +16,14 @@ CastTransportSenderIPC::ClientCallbacks::~ClientCallbacks() {}
 
 CastTransportSenderIPC::CastTransportSenderIPC(
     const net::IPEndPoint& remote_end_point,
+    scoped_ptr<base::DictionaryValue> options,
     const media::cast::CastTransportStatusCallback& status_cb,
     const media::cast::BulkRawEventsCallback& raw_events_cb)
     : status_callback_(status_cb), raw_events_callback_(raw_events_cb) {
   if (CastIPCDispatcher::Get()) {
     channel_id_ = CastIPCDispatcher::Get()->AddSender(this);
   }
-  Send(new CastHostMsg_New(channel_id_, remote_end_point));
+  Send(new CastHostMsg_New(channel_id_, remote_end_point, *options));
 }
 
 CastTransportSenderIPC::~CastTransportSenderIPC() {