Integrate QualityScaler into VideoToolboxEncoder.

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h

Index: webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h
diff --git a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h
index d54fa612c3d4172dd347f9d02abbc342711d719a..5dfcf9f60a032e6ffec98b5644b9813003e2a677 100644
--- a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h
+++ b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.h
@@ -12,9 +12,12 @@
 #ifndef WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_H264_VIDEO_TOOLBOX_ENCODER_H_
 #define WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_H264_VIDEO_TOOLBOX_ENCODER_H_
 
+#include "webrtc/base/criticalsection.h"
 #include "webrtc/common_video/include/bitrate_adjuster.h"
 #include "webrtc/common_video/rotation.h"
 #include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
+#include "webrtc/modules/video_coding/utility/h264_bitstream_parser.h"
+#include "webrtc/modules/video_coding/utility/quality_scaler.h"
 
 #if defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
 
@@ -44,6 +47,7 @@ class H264VideoToolboxEncoder : public H264Encoder {
 
   int RegisterEncodeCompleteCallback(EncodedImageCallback* callback) override;
 
+  void OnDroppedFrame() override;
   int SetChannelParameters(uint32_t packet_loss, int64_t rtt) override;
 
   int SetRates(uint32_t new_bitrate_kbit, uint32_t frame_rate) override;
@@ -66,6 +70,7 @@ class H264VideoToolboxEncoder : public H264Encoder {
   int ResetCompressionSession();
   void ConfigureCompressionSession();
   void DestroyCompressionSession();
+  const VideoFrame& GetScaledFrameOnEncode(const VideoFrame& frame);
   void SetBitrateBps(uint32_t bitrate_bps);
   void SetEncoderBitrateBps(uint32_t bitrate_bps);
 
@@ -76,6 +81,10 @@ class H264VideoToolboxEncoder : public H264Encoder {
   uint32_t encoder_bitrate_bps_;
   int32_t width_;
   int32_t height_;
+
+  rtc::CriticalSection quality_scaler_crit_;
+  QualityScaler quality_scaler_ GUARDED_BY(quality_scaler_crit_);
+  H264BitstreamParser h264_bitstream_parser_;
 };  // H264VideoToolboxEncoder
 
 }  // namespace webrtc