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

media/cast/net/cast_transport_sender_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This class maintains a send transport for audio and video in a Cast
 // Streaming session.
 // Audio, video frames and RTCP messages are submitted to this object
 // and then packetized and paced to the underlying UDP socket.
 //
 // The hierarchy of send transport in a Cast Streaming session:
@@ skipping 40 matching lines @@
   // |external_transport| is only used for testing.
   // |raw_events_callback|: Raw events will be returned on this callback
   // which will be invoked every |raw_events_callback_interval|.
   // This can be a null callback, i.e. if user is not interested in raw events.
   // |raw_events_callback_interval|: This can be |base::TimeDelta()| if
   // |raw_events_callback| is a null callback.
   CastTransportSenderImpl(
       net::NetLog* net_log,
       base::TickClock* clock,
       const net::IPEndPoint& remote_end_point,
+      scoped_ptr<base::DictionaryValue> options,
       const CastTransportStatusCallback& status_callback,
       const BulkRawEventsCallback& raw_events_callback,
       base::TimeDelta raw_events_callback_interval,
       const scoped_refptr<base::SingleThreadTaskRunner>& transport_task_runner,
       PacketSender* external_transport);
 
   virtual ~CastTransportSenderImpl();
 
   virtual void InitializeAudio(const CastTransportRtpConfig& config,
                                const RtcpCastMessageCallback& cast_message_cb,
@@ skipping 88 matching lines @@
 
   base::WeakPtrFactory<CastTransportSenderImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CastTransportSenderImpl);
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_NET_CAST_TRANSPORT_IMPL_H_