Add QP for libvpx VP8 decoder.

webrtc/modules/video_coding/codecs/test/videoprocessor.cc

Index: webrtc/modules/video_coding/codecs/test/videoprocessor.cc
diff --git a/webrtc/modules/video_coding/codecs/test/videoprocessor.cc b/webrtc/modules/video_coding/codecs/test/videoprocessor.cc
index 35bf5593664a8b2cc6cbefebad5e3791f75ccb94..4d9e5f017784b1010bf7224593465f83338321ee 100644
--- a/webrtc/modules/video_coding/codecs/test/videoprocessor.cc
+++ b/webrtc/modules/video_coding/codecs/test/videoprocessor.cc
@@ -444,6 +444,13 @@ int32_t VideoProcessorImpl::VideoProcessorDecodeCompleteCallback::Decoded(
   video_processor_->FrameDecoded(image);
   return 0;
 }
+void VideoProcessorImpl::VideoProcessorDecodeCompleteCallback::Decoded(
+    VideoFrame& frame,
+    rtc::Optional<int32_t> decode_time_ms,
+    rtc::Optional<uint8_t> qp) {
+    // Forward to parent class.
+    video_processor_->FrameDecoded(frame);
+}
 
 }  // namespace test
 }  // namespace webrtc