Add QP sum stats for received streams.

webrtc/modules/video_coding/generic_decoder.cc

Index: webrtc/modules/video_coding/generic_decoder.cc
diff --git a/webrtc/modules/video_coding/generic_decoder.cc b/webrtc/modules/video_coding/generic_decoder.cc
index b95571b8f73793718d318eedc82fff249e9a9f17..502be884262f6a4c0417fec1025cfa04624a5aa8 100644
--- a/webrtc/modules/video_coding/generic_decoder.cc
+++ b/webrtc/modules/video_coding/generic_decoder.cc
@@ -48,6 +48,12 @@ int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage) {
 
 int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
                                          int64_t decode_time_ms) {
+  return Decoded(decodedImage, decode_time_ms, -1);
+}
+
+int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
+                                         int64_t decode_time_ms,
+                                         int qp) {
   TRACE_EVENT_INSTANT1("webrtc", "VCMDecodedFrameCallback::Decoded",
                        "timestamp", decodedImage.timestamp());
   // TODO(holmer): We should improve this so that we can handle multiple
@@ -79,7 +85,7 @@ int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
   // TODO(sakal): Investigate why callback is NULL sometimes and replace if
   // statement with a DCHECK.
   if (callback) {
-    callback->FrameToRender(decodedImage);
+    callback->FrameToRender(decodedImage, qp);
   } else {
     LOG(LS_WARNING) << "No callback, dropping frame.";
   }