Add VideoReader and VideoWriter interfaces.

remoting/protocol/rtp_writer.h

Index: remoting/protocol/rtp_writer.h
diff --git a/remoting/protocol/rtp_writer.h b/remoting/protocol/rtp_writer.h
index 5ba7501a48641dc1ca1262c5db8b721a5f12bf14..6bcd7ecff387f6bcb0a9870a5c43ba654b74f355 100644
--- a/remoting/protocol/rtp_writer.h
+++ b/remoting/protocol/rtp_writer.h
@@ -19,8 +19,11 @@ class RtpWriter {
   // to.
   void Init(net::Socket* rtp_socket, net::Socket* rtcp_socket);
 
-  void SendPacket(const char* buffer, int packet_size,
-                  uint32 timestamp);
+  // Sends next packet.
+  void SendPacket(const char* payload, int payload_size, uint32 timestamp);
+
+  // Returns number of packets queued in the buffer.
+  int GetPendingPackets();
 
   // Stop writing and drop pending data. Must be called from the same thread as
   // Init().