Add QP sum stats for received streams.

webrtc/media/engine/videodecodersoftwarefallbackwrapper_unittest.cc

Index: webrtc/media/engine/videodecodersoftwarefallbackwrapper_unittest.cc
diff --git a/webrtc/media/engine/videodecodersoftwarefallbackwrapper_unittest.cc b/webrtc/media/engine/videodecodersoftwarefallbackwrapper_unittest.cc
index ccdf017d3dd25034a1bf339929d21889e747a7de..6af50db0765407397092608e0b22e9984fa2213e 100644
--- a/webrtc/media/engine/videodecodersoftwarefallbackwrapper_unittest.cc
+++ b/webrtc/media/engine/videodecodersoftwarefallbackwrapper_unittest.cc
@@ -141,6 +141,12 @@ TEST_F(VideoDecoderSoftwareFallbackWrapperTest,
       RTC_NOTREACHED();
       return -1;
     }
+    int32_t Decoded(webrtc::VideoFrame& decodedImage,
+                    int64_t decode_time_ms,
+                    int qp) override {
+      RTC_NOTREACHED();
+      return -1;
+    }
   } callback, callback2;
 
   VideoCodec codec = {};