Extract common simulcast logic from VP8 wrapper and simulcast adapter

webrtc/video/video_send_stream.cc

Index: webrtc/video/video_send_stream.cc
diff --git a/webrtc/video/video_send_stream.cc b/webrtc/video/video_send_stream.cc
index 9ffe8a34c07f1139d19a4337f9894cc36507aa48..13abfcdb4773a2ba12f8435b5f7cb73deded5271 100644
--- a/webrtc/video/video_send_stream.cc
+++ b/webrtc/video/video_send_stream.cc
@@ -23,6 +23,7 @@
 #include "webrtc/modules/congestion_controller/include/congestion_controller.h"
 #include "webrtc/modules/pacing/packet_router.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
+#include "webrtc/modules/video_coding/utility/simulcast_state.h"
 #include "webrtc/modules/utility/include/process_thread.h"
 #include "webrtc/video/call_stats.h"
 #include "webrtc/video/video_capture_input.h"
@@ -604,6 +605,7 @@ void VideoSendStream::ReconfigureVideoEncoder(
     pending_encoder_settings_ = rtc::Optional<EncoderSettings>(
         {video_codec, config.min_transmit_bitrate_bps, config.streams});
   }
+  payload_router_.UpdateSimulcastState(SimulcastState(video_codec));
   encoder_wakeup_event_.Set();
 }