Add QP sum stats for received streams.

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

Index: webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
diff --git a/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h b/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
index d140b0a5292683a2b507de9f534681cd3a347749..4a572e97a0b69af8e77d4d76e692b1aee54b200b 100644
--- a/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
+++ b/webrtc/modules/video_coding/codecs/vp8/simulcast_unittest.h
@@ -145,6 +145,12 @@ class Vp8TestDecodedImageCallback : public DecodedImageCallback {
     RTC_NOTREACHED();
     return -1;
   }
+  int32_t Decoded(VideoFrame& decoded_image,
+                  int64_t decode_time_ms,
+                  int qp) override {
+    RTC_NOTREACHED();
+    return -1;
+  }
   int DecodedFrames() { return decoded_frames_; }
 
  private: