Extract common simulcast logic from VP8 wrapper and simulcast adapter

webrtc/modules/video_coding/codecs/vp8/vp8_impl.h

Index: webrtc/modules/video_coding/codecs/vp8/vp8_impl.h
diff --git a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.h b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.h
index f8af642253824c8bb96a72c17d3e91ef1ea6b294..da1edb3106a916589b201226074219ba633a9cd6 100644
--- a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.h
+++ b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.h
@@ -28,6 +28,8 @@
 #include "webrtc/modules/video_coding/codecs/vp8/reference_picture_selection.h"
 #include "webrtc/modules/video_coding/utility/frame_dropper.h"
 #include "webrtc/modules/video_coding/utility/quality_scaler.h"
+#include "webrtc/modules/video_coding/utility/simulcast_state.h"
+
 #include "webrtc/video_frame.h"
 
 namespace webrtc {
@@ -86,9 +88,6 @@ class VP8EncoderImpl : public VP8Encoder {
   int GetEncodedPartitions(const VideoFrame& input_image,
                            bool only_predicting_from_key_frame);
 
-  // Set the stream state for stream |stream_idx|.
-  void SetStreamState(bool send_stream, int stream_idx);
-
   uint32_t MaxIntraTarget(uint32_t optimal_buffer_size);
 
   EncodedImageCallback* encoded_complete_callback_;
@@ -102,14 +101,11 @@ class VP8EncoderImpl : public VP8Encoder {
   int token_partitions_;
   ReferencePictureSelection rps_;
   std::vector<TemporalLayers*> temporal_layers_;
+  SimulcastState simulcast_state_;
   bool down_scale_requested_;
   uint32_t down_scale_bitrate_;
-  FrameDropper tl0_frame_dropper_;
-  FrameDropper tl1_frame_dropper_;
   std::vector<uint16_t> picture_id_;
   std::vector<int> last_key_frame_picture_id_;
-  std::vector<bool> key_frame_request_;
-  std::vector<bool> send_stream_;
   std::vector<int> cpu_speed_;
   std::vector<vpx_image_t> raw_images_;
   std::vector<EncodedImage> encoded_images_;