Reland of Add QP sum stats for received streams.

webrtc/video/video_stream_decoder.cc

Index: webrtc/video/video_stream_decoder.cc
diff --git a/webrtc/video/video_stream_decoder.cc b/webrtc/video/video_stream_decoder.cc
index 2c7f84b8a6300d2e2f99bc55fc5d26043b1427ab..b0308f25d85fba6bad556bc4d0118fe5d1d026d9 100644
--- a/webrtc/video/video_stream_decoder.cc
+++ b/webrtc/video/video_stream_decoder.cc
@@ -73,8 +73,11 @@
 // callback won't necessarily be called from the decoding thread. The decoding
 // thread may have held the lock when calling VideoDecoder::Decode, Reset, or
 // Release. Acquiring the same lock in the path of decode callback can deadlock.
-int32_t VideoStreamDecoder::FrameToRender(VideoFrame& video_frame) {  // NOLINT
+int32_t VideoStreamDecoder::FrameToRender(VideoFrame& video_frame,
+                                          rtc::Optional<uint8_t> qp) {
+  receive_stats_callback_->OnDecodedFrame(qp);
   incoming_video_stream_->OnFrame(video_frame);
+
   return 0;
 }