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

chrome/renderer/media/cast_session.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_SESSION_H_
 #define CHROME_RENDERER_MEDIA_CAST_SESSION_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 49 matching lines @@
   // the main thread.
   // |StartUDP()| must be called before these methods.
   void StartAudio(const media::cast::AudioSenderConfig& config,
                   const AudioFrameInputAvailableCallback& callback,
                   const ErrorCallback& error_callback);
   void StartVideo(const media::cast::VideoSenderConfig& config,
                   const VideoFrameInputAvailableCallback& callback,
                   const ErrorCallback& error_callback);
 
   // This will create the Cast transport and connect to |remote_endpoint|.
+  // |options| is a colon-separated string opftions passed down to the
+  // cast udp transport.
   // Must be called before initialization of audio or video.
-  void StartUDP(const net::IPEndPoint& remote_endpoint);
+  void StartUDP(const net::IPEndPoint& remote_endpoint,
+                const std::string& options);

[Alpha Left Google, 2014/09/09 00:30:45]

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

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

Done.

 
   // Creates or destroys event subscriber for the audio or video stream.
   // |is_audio|: true if the event subscriber is for audio. Video otherwise.
   // |enable|: If true, creates an event subscriber. Otherwise destroys
   // existing subscriber and discards logs.
   void ToggleLogging(bool is_audio, bool enable);
 
   // Returns raw event logs in serialized format for either the audio or video
   // stream since last call and returns result in |callback|. Also attaches
   // |extra_data| to the log.
@@ skipping 14 matching lines @@
   // because it is owned by this object.
   scoped_ptr<CastSessionDelegate> delegate_;
 
   // Proxy to the IO message loop.
   const scoped_refptr<base::MessageLoopProxy> io_message_loop_proxy_;
 
   DISALLOW_COPY_AND_ASSIGN(CastSession);
 };
 
 #endif  // CHROME_RENDERER_MEDIA_CAST_SESSION_H_