Cast:Adding signaling and infrastructure for adjustable delay

media/cast/video_receiver/video_receiver.h

Index: media/cast/video_receiver/video_receiver.h
diff --git a/media/cast/video_receiver/video_receiver.h b/media/cast/video_receiver/video_receiver.h
index 3f4d8123921c13a14c22ffec9a71779abe9f238a..a24b7705c5bcc3be8dd6612b3a440b0049028348 100644
--- a/media/cast/video_receiver/video_receiver.h
+++ b/media/cast/video_receiver/video_receiver.h
@@ -33,13 +33,18 @@ class Rtcp;
 class RtpReceiverStatistics;
 class VideoDecoder;
 
+// Callback used by the video receiver to inform the audio receiver of the new
+// delay used to compute the playout and render times.
+typedef base::Callback<void(base::TimeDelta)> SetTargetDelayCallback;
+
 // Should only be called from the Main cast thread.
 class VideoReceiver : public base::NonThreadSafe,
                       public base::SupportsWeakPtr<VideoReceiver> {
  public:
   VideoReceiver(scoped_refptr<CastEnvironment> cast_environment,
                 const VideoReceiverConfig& video_config,
-                transport::PacedPacketSender* const packet_sender);
+                transport::PacedPacketSender* const packet_sender,
+                const SetTargetDelayCallback& target_delay_cb);
 
   virtual ~VideoReceiver();
 
@@ -98,6 +103,10 @@ class VideoReceiver : public base::NonThreadSafe,
   // Actually send the next RTCP report.
   void SendNextRtcpReport();
 
+  // Update the target delay based on past information. Will also update the
+  // rtcp module and the audio receiver.
+  void UpdateTargetDelay();
+
   scoped_ptr<VideoDecoder> video_decoder_;
   scoped_refptr<CastEnvironment> cast_environment_;
 
@@ -121,6 +130,7 @@ class VideoReceiver : public base::NonThreadSafe,
   base::TimeTicks time_incoming_packet_;
   uint32 incoming_rtp_timestamp_;
   base::TimeTicks last_render_time_;
+  SetTargetDelayCallback target_delay_cb_;
 
   // This mapping allows us to log kVideoAckSent as a frame event. In addition
   // it allows the event to be transmitted via RTCP.