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

chrome/renderer/media/cast_udp_transport.h

 // Copyright 2013 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.
 
 #ifndef CHROME_RENDERER_MEDIA_CAST_UDP_TRANSPORT_H_
 #define CHROME_RENDERER_MEDIA_CAST_UDP_TRANSPORT_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "net/base/ip_endpoint.h"
 
 class CastSession;
 
 // This class represents the transport mechanism used by Cast RTP streams
 // to connect to a remote client. It specifies the destination address
 // and network protocol used to send Cast RTP streams.
 class CastUdpTransport {
  public:
   explicit CastUdpTransport(const scoped_refptr<CastSession>& session);
   virtual ~CastUdpTransport();
 
   // Specify the remote IP address and port.
   void SetDestination(const net::IPEndPoint& remote_address);
 
+  // Set options.
+  void SetOptions(const std::string& options);

[Alpha Left Google, 2014/09/09 00:30:46]

I suggest this be base::DictionaryValue which is a key value pair data
structure.

[hubbe, 2014/09/09 20:10:01]

Done.

+
  private:
   const scoped_refptr<CastSession> cast_session_;
   net::IPEndPoint remote_address_;
+  std::string options_;
   base::WeakPtrFactory<CastUdpTransport> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CastUdpTransport);
 };
 
 #endif  // CHROME_RENDERER_MEDIA_CAST_UDP_TRANSPORT_H_