Add QP sum stats for received streams.

webrtc/video_decoder.h

Index: webrtc/video_decoder.h
diff --git a/webrtc/video_decoder.h b/webrtc/video_decoder.h
index b8d2c96b1be8da1cb27138f0550302ebe7b378c1..70c09129f788908de537b08aa4a68e4c7c42a703 100644
--- a/webrtc/video_decoder.h
+++ b/webrtc/video_decoder.h
@@ -35,11 +35,18 @@ class DecodedImageCallback {
   // decode time excluding waiting time for any previous pending frame to
   // return. This is necessary for breaking positive feedback in the delay
   // estimation when the decoder has a single output buffer.
-  // TODO(perkj): Remove default implementation when chromium has been updated.
   virtual int32_t Decoded(VideoFrame& decodedImage, int64_t decode_time_ms) {
     // The default implementation ignores custom decode time value.
     return Decoded(decodedImage);
   }
+  // TODO(sakal): Remove other implementations when upstream projects have been
+  // updated.
+  virtual void Decoded(VideoFrame& decodedImage,
+                       rtc::Optional<int32_t> decode_time_ms,
+                       rtc::Optional<uint8_t> qp) {
+    Decoded(decodedImage,
+            decode_time_ms ? static_cast<int32_t>(*decode_time_ms) : -1);
+  }
 
   virtual int32_t ReceivedDecodedReferenceFrame(const uint64_t pictureId) {
     return -1;