Add QP sum stats for received streams.

webrtc/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc

Index: webrtc/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc b/webrtc/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
index de612f0404bff79c2404ba18c2e44e34f6259861..8e50239e1099c88f706f9d0fb8c65aed2c2f80fd 100644
--- a/webrtc/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
@@ -97,6 +97,12 @@ class Vp8UnitTestDecodeCompleteCallback : public webrtc::DecodedImageCallback {
     RTC_NOTREACHED();
     return -1;
   }
+  int32_t Decoded(VideoFrame& frame,
+                  rtc::Optional<int32_t> decode_time_ms,
+                  rtc::Optional<uint8_t> qp) override {
+    RTC_NOTREACHED();
+    return -1;
+  }
   bool DecodeComplete();
 
  private: