Adding support for RTCRtpEncodingParameters.active flag.

webrtc/api/rtpparameters.h

Index: webrtc/api/rtpparameters.h
diff --git a/webrtc/api/rtpparameters.h b/webrtc/api/rtpparameters.h
index e71a1aebbaf23bbaa589759112b762916b7d25c0..2c29d9843d9ee597c81e313e2476f05344065b40 100644
--- a/webrtc/api/rtpparameters.h
+++ b/webrtc/api/rtpparameters.h
@@ -18,6 +18,7 @@ namespace webrtc {
 // These structures are defined as part of the RtpSender interface.
 // See http://w3c.github.io/webrtc-pc/#rtcrtpsender-interface for details.
 struct RtpEncodingParameters {
+  bool active = true;
   int max_bitrate_bps = -1;
 };