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..777004f8a121f6d2681828e791aa37ac0a8618d6 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 +97,10 @@ class Vp8UnitTestDecodeCompleteCallback : public webrtc::DecodedImageCallback {
     RTC_NOTREACHED();
     return -1;
   }
+  int32_t Decoded(VideoFrame& frame, int64_t decode_time_ms, int qp) override {
+    RTC_NOTREACHED();
+    return -1;
+  }
   bool DecodeComplete();
 
  private: