[Cast] Limit frames in flight by duration, and not by number of frames.

media/cast/net/cast_transport_config.cc

Index: media/cast/net/cast_transport_config.cc
diff --git a/media/cast/net/cast_transport_config.cc b/media/cast/net/cast_transport_config.cc
index b6c9a07aa60ff701de5b9f3b05efd73a7a46d321..2543f285f79baf98dc3894f78ce999ad41585ef4 100644
--- a/media/cast/net/cast_transport_config.cc
+++ b/media/cast/net/cast_transport_config.cc
@@ -8,7 +8,7 @@ namespace media {
 namespace cast {
 
 CastTransportRtpConfig::CastTransportRtpConfig()
-    : ssrc(0), feedback_ssrc(0), rtp_payload_type(0), stored_frames(0) {}
+    : ssrc(0), feedback_ssrc(0), rtp_payload_type(0) {}
 
 CastTransportRtpConfig::~CastTransportRtpConfig() {}