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..7acacbb40947716528ba7eaa1a45dcc61c50488e 100644
--- a/webrtc/modules/video_coding/generic_decoder.cc
+++ b/webrtc/modules/video_coding/generic_decoder.cc
@@ -48,6 +48,15 @@ int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage) {
 
 int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
                                          int64_t decode_time_ms) {
+  return Decoded(decodedImage,
+                 decode_time_ms >= 0 ? rtc::Optional<int32_t>(decode_time_ms)
+                                     : rtc::Optional<int32_t>(),
+                 rtc::Optional<uint8_t>());
+}
+
+int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
+                                         rtc::Optional<int32_t> decode_time_ms,
+                                         rtc::Optional<uint8_t> qp) {
   TRACE_EVENT_INSTANT1("webrtc", "VCMDecodedFrameCallback::Decoded",
                        "timestamp", decodedImage.timestamp());
   // TODO(holmer): We should improve this so that we can handle multiple
@@ -67,11 +76,11 @@ int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
   }
 
   const int64_t now_ms = _clock->TimeInMilliseconds();
-  if (decode_time_ms < 0) {
+  if (!decode_time_ms) {
     decode_time_ms =
-        static_cast<int32_t>(now_ms - frameInfo->decodeStartTimeMs);
+        rtc::Optional<int32_t>(now_ms - frameInfo->decodeStartTimeMs);
   }
-  _timing->StopDecodeTimer(decodedImage.timestamp(), decode_time_ms, now_ms,
+  _timing->StopDecodeTimer(decodedImage.timestamp(), *decode_time_ms, now_ms,
                            frameInfo->renderTimeMs);
 
   decodedImage.set_render_time_ms(frameInfo->renderTimeMs);
@@ -79,7 +88,7 @@ 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.";
   }