Add QP stats for sent video streams to StatsReport.

webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc

Index: webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
index 1869a382f2368ba4311db4084a04f80772388f3e..3b5e66dbb2c054501b69f7adf0761d2b60c3d6ed 100644
--- a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
@@ -1003,6 +1003,7 @@ int VP8EncoderImpl::GetEncodedPartitions(const VideoFrame& input_image,
             codec_.simulcastStream[stream_idx].height;
         encoded_images_[encoder_idx]._encodedWidth =
             codec_.simulcastStream[stream_idx].width;
+        encoded_images_[encoder_idx].qp_ = qp;
         encoded_complete_callback_->Encoded(encoded_images_[encoder_idx],
                                             &codec_specific, &frag_info);
       } else if (codec_.mode == kScreensharing) {