Implement qpSum stat for video send ssrc stats.

webrtc/video/send_statistics_proxy_unittest.cc

Index: webrtc/video/send_statistics_proxy_unittest.cc
diff --git a/webrtc/video/send_statistics_proxy_unittest.cc b/webrtc/video/send_statistics_proxy_unittest.cc
index 84a315683791887254e3a86282e21dd648672343..b5231d68c28be2b0134d1cd8ae2840da64bd0d39 100644
--- a/webrtc/video/send_statistics_proxy_unittest.cc
+++ b/webrtc/video/send_statistics_proxy_unittest.cc
@@ -311,6 +311,18 @@ TEST_F(SendStatisticsProxyTest, OnSendEncodedImageIncreasesFramesEncoded) {
   }
 }
 
+TEST_F(SendStatisticsProxyTest, OnSendEncodedImageIncreasesQpSum) {
+  EncodedImage encoded_image;
+  CodecSpecificInfo codec_info;
+  EXPECT_EQ(0, statistics_proxy_->GetStats().qp_sum);
+  encoded_image.qp_ = 3;
+  statistics_proxy_->OnSendEncodedImage(encoded_image, &codec_info);
+  EXPECT_EQ(3, statistics_proxy_->GetStats().qp_sum);
+  encoded_image.qp_ = 127;
+  statistics_proxy_->OnSendEncodedImage(encoded_image, &codec_info);
+  EXPECT_EQ(130, statistics_proxy_->GetStats().qp_sum);
+}
+
 TEST_F(SendStatisticsProxyTest, SwitchContentTypeUpdatesHistograms) {
   const int kWidth = 640;
   const int kHeight = 480;