Refactor: simplify interface of SenderRtcpSession and CastTransport.

media/cast/sender/frame_sender.cc

Index: media/cast/sender/frame_sender.cc
diff --git a/media/cast/sender/frame_sender.cc b/media/cast/sender/frame_sender.cc
index 48d5d3cfec2a1e00cef8d520d14a890f422f90d1..6f8fcd9932b1a1542a4af6c1426bda524f09092d 100644
--- a/media/cast/sender/frame_sender.cc
+++ b/media/cast/sender/frame_sender.cc
@@ -32,6 +32,27 @@ const int kMaxFrameBurst = 5;
 // Convenience macro used in logging statements throughout this file.
 #define SENDER_SSRC (is_audio_ ? "AUDIO[" : "VIDEO[") << ssrc_ << "] "
 
+FrameSender::RtcpObserver::RtcpObserver(base::WeakPtr<FrameSender> frame_sender)
+    : frame_sender_(frame_sender) {}
+
+FrameSender::RtcpObserver::~RtcpObserver() {}
+
+void FrameSender::RtcpObserver::OnCastMessageReceived(
+    const RtcpCastMessage& cast_message) {
+  if (frame_sender_)
+    frame_sender_->OnReceivedCastFeedback(cast_message);
+}
+
+void FrameSender::RtcpObserver::OnRttReceived(base::TimeDelta round_trip_time) {
+  if (frame_sender_)
+    frame_sender_->OnMeasuredRoundTripTime(round_trip_time);
+}
+
+void FrameSender::RtcpObserver::OnPliReceived() {
+  if (frame_sender_)
+    frame_sender_->OnReceivedPli();
+}
+
 FrameSender::FrameSender(scoped_refptr<CastEnvironment> cast_environment,
                          bool is_audio,
                          CastTransport* const transport_sender,