Add stats for average QP per frame for VP8 (for received video streams).

webrtc/video/video_receive_stream.h

Index: webrtc/video/video_receive_stream.h
diff --git a/webrtc/video/video_receive_stream.h b/webrtc/video/video_receive_stream.h
index 011788d6b89708324dca49970d4993095e95e45d..fbea6042672f493b519d1eaf21cb58b10667c48f 100644
--- a/webrtc/video/video_receive_stream.h
+++ b/webrtc/video/video_receive_stream.h
@@ -22,6 +22,7 @@
 #include "webrtc/system_wrappers/interface/clock.h"
 #include "webrtc/video/encoded_frame_callback_adapter.h"
 #include "webrtc/video/receive_statistics_proxy.h"
+#include "webrtc/video_encoder.h"
 #include "webrtc/video_engine/vie_channel.h"
 #include "webrtc/video_engine/vie_channel_group.h"
 #include "webrtc/video_engine/vie_encoder.h"
@@ -35,7 +36,8 @@ namespace internal {
 
 class VideoReceiveStream : public webrtc::VideoReceiveStream,
                            public I420FrameCallback,
-                           public VideoRenderCallback {
+                           public VideoRenderCallback,
+                           public EncodedImageCallback {
  public:
   VideoReceiveStream(int num_cpu_cores,
                      ChannelGroup* channel_group,
@@ -63,6 +65,11 @@ class VideoReceiveStream : public webrtc::VideoReceiveStream,
   int RenderFrame(const uint32_t /*stream_id*/,
                   const VideoFrame& video_frame) override;
 
+  // Overrides EncodedImageCallback.
+  int32_t Encoded(const EncodedImage& encoded_image,
+                  const CodecSpecificInfo* codec_specific_info,
+                  const RTPFragmentationHeader* fragmentation) override;
+
   const Config& config() const { return config_; }
 
   void SetSyncChannel(VoiceEngine* voice_engine, int audio_channel_id);