[Cast] Cleanup: Remove TransportXXXXXSender, an unnecessary layer of indirection.

media/cast/transport/cast_transport_config.cc

Index: media/cast/transport/cast_transport_config.cc
diff --git a/media/cast/transport/cast_transport_config.cc b/media/cast/transport/cast_transport_config.cc
index 2c40a19d0ab230b0a118fdba27febb3f1a650b74..16e90347137bd457c736f910bcdb85145807c16e 100644
--- a/media/cast/transport/cast_transport_config.cc
+++ b/media/cast/transport/cast_transport_config.cc
@@ -41,6 +41,15 @@ EncodedFrame::EncodedFrame()
 
 EncodedFrame::~EncodedFrame() {}
 
+void EncodedFrame::CopyMetadataTo(EncodedFrame* dest) const {
+  DCHECK(dest);
+  dest->dependency = this->dependency;
+  dest->frame_id = this->frame_id;
+  dest->referenced_frame_id = this->referenced_frame_id;
+  dest->rtp_timestamp = this->rtp_timestamp;
+  dest->reference_time = this->reference_time;
+}
+
 RtcpSenderInfo::RtcpSenderInfo()
     : ntp_seconds(0),
       ntp_fraction(0),