Add |protected_by_flexfec| flag to VideoReceiveStream::Config.

webrtc/video_receive_stream.h

Index: webrtc/video_receive_stream.h
diff --git a/webrtc/video_receive_stream.h b/webrtc/video_receive_stream.h
index 12629d06378085b2a0bbee04d4877284390593e5..33d779d9b39444ab09a53d8457e879034dcf41f2 100644
--- a/webrtc/video_receive_stream.h
+++ b/webrtc/video_receive_stream.h
@@ -147,6 +147,9 @@ class VideoReceiveStream {
       // SSRC for retransmissions.
       uint32_t rtx_ssrc = 0;
 
+      // Set if the stream is protected using FlexFEC.
+      bool protected_by_flexfec = false;
+
       // Map from video payload type (apt) -> RTX payload type (pt).
       // For RTX to be enabled, both an SSRC and this mapping are needed.
       std::map<int, int> rtx_payload_types;