Enable setting the maximum bitrate limit in RtpSender.

webrtc/media/engine/webrtcvideoengine2.h

Index: webrtc/media/engine/webrtcvideoengine2.h
diff --git a/webrtc/media/engine/webrtcvideoengine2.h b/webrtc/media/engine/webrtcvideoengine2.h
index 3dd05f2400bfaa88808a9880260e764390820b7a..f154bbeb4f17700cb61e85b92f5fd1fd5e8d81b5 100644
--- a/webrtc/media/engine/webrtcvideoengine2.h
+++ b/webrtc/media/engine/webrtcvideoengine2.h
@@ -145,6 +145,9 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
 
   bool SetSendParameters(const VideoSendParameters& params) override;
   bool SetRecvParameters(const VideoRecvParameters& params) override;
+  webrtc::RTCRtpParameters GetRtpParameters(uint32_t ssrc) override;
+  bool SetRtpParameters(uint32_t ssrc,
+                        const webrtc::RTCRtpParameters& parameters) override;
   bool GetSendCodec(VideoCodec* send_codec) override;
   bool SetSend(bool send) override;
   bool SetVideoSend(uint32_t ssrc,
@@ -254,6 +257,11 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
     void Start();
     void Stop();
 
+    webrtc::RTCRtpParameters rtp_parameters() const { return rtp_parameters_; }
+    void set_rtp_parameters(const webrtc::RTCRtpParameters& parameters) {
+      rtp_parameters_ = parameters;
+    }
+
     // Implements webrtc::LoadObserver.
     void OnLoadUpdate(Load load) override;
 
@@ -381,6 +389,8 @@ class WebRtcVideoChannel2 : public VideoMediaChannel, public webrtc::Transport {
     // The timestamp of the last frame received
     // Used to generate timestamp for the black frame when capturer is removed
     int64_t last_frame_timestamp_ms_ GUARDED_BY(lock_);
+
+    webrtc::RTCRtpParameters rtp_parameters_;
   };
 
   // Wrapper for the receiver part, contains configs etc. that are needed to