Add QP sum stats for received streams.

webrtc/media/engine/webrtcvideoengine2_unittest.cc

Index: webrtc/media/engine/webrtcvideoengine2_unittest.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2_unittest.cc b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
index 4b73faa92ad80765b8257964f5e7d2dab4076dce..6dbacc4d1ee141e10c9692d21dc6f5b373d3d89c 100644
--- a/webrtc/media/engine/webrtcvideoengine2_unittest.cc
+++ b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
@@ -3423,6 +3423,7 @@ TEST_F(WebRtcVideoChannel2Test, GetStatsTranslatesDecodeStatsCorrectly) {
   stats.frame_counts.delta_frames = 12;
   stats.frames_rendered = 13;
   stats.frames_decoded = 14;
+  stats.qp_sum = rtc::Optional<uint64_t>(15);
   stream->SetStats(stats);
 
   cricket::VideoMediaInfo info;
@@ -3442,6 +3443,7 @@ TEST_F(WebRtcVideoChannel2Test, GetStatsTranslatesDecodeStatsCorrectly) {
             info.receivers[0].frames_received);
   EXPECT_EQ(stats.frames_rendered, info.receivers[0].frames_rendered);
   EXPECT_EQ(stats.frames_decoded, info.receivers[0].frames_decoded);
+  EXPECT_EQ(stats.qp_sum, info.receivers[0].qp_sum);
 }
 
 TEST_F(WebRtcVideoChannel2Test, GetStatsTranslatesReceivePacketStatsCorrectly) {