Make |rtcp_send_transport| mandatory in FlexfecReceiveStream::Config.

webrtc/call/flexfec_receive_stream.h

Index: webrtc/call/flexfec_receive_stream.h
diff --git a/webrtc/call/flexfec_receive_stream.h b/webrtc/call/flexfec_receive_stream.h
index 20a57f2c150d4e90e919b4f9a6555568e154678f..b724f9055b6f96a135283a746ce78aec47845813 100644
--- a/webrtc/call/flexfec_receive_stream.h
+++ b/webrtc/call/flexfec_receive_stream.h
@@ -29,8 +29,15 @@ class FlexfecReceiveStream {
   };
 
   struct Config {
+    explicit Config(Transport* rtcp_send_transport)
+        : rtcp_send_transport(rtcp_send_transport) {}
+
     std::string ToString() const;
 
+    // Returns true if all RTP information is available in order to
+    // enable receiving FlexFEC.
+    bool IsCompleteAndEnabled() const;

[stefan-webrtc, 2016/12/22 09:14:54]

Is this used for anything but tests? If not, I'd prefer to have it part of the
test code.

[brandtr, 2017/01/03 10:01:05]

Yes, it's used here:
https://codereview.webrtc.org/2589713003/diff/280001/webrtc/media/engine/webr...

+
     // Payload type for FlexFEC.
     int payload_type = -1;