Add stats for average QP per frame for VP8 (for received video streams).

webrtc/modules/video_coding/utility/qp_parser.cc

Index: webrtc/modules/video_coding/utility/qp_parser.cc
diff --git a/webrtc/modules/audio_coding/codecs/isac/locked_bandwidth_info.cc b/webrtc/modules/video_coding/utility/qp_parser.cc
similarity index 51%
copy from webrtc/modules/audio_coding/codecs/isac/locked_bandwidth_info.cc
copy to webrtc/modules/video_coding/utility/qp_parser.cc
index 78b415c4c950224a459759cb681b8f04f807b6b4..62ce31351e3c16f31297b0ebca4f50132409f830 100644
--- a/webrtc/modules/audio_coding/codecs/isac/locked_bandwidth_info.cc
+++ b/webrtc/modules/video_coding/utility/qp_parser.cc
@@ -8,15 +8,21 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "webrtc/modules/audio_coding/codecs/isac/locked_bandwidth_info.h"
+#include "webrtc/modules/video_coding/utility/include/qp_parser.h"
+
+#include "webrtc/common_types.h"
+#include "webrtc/modules/video_coding/utility/include/vp8_header_parser.h"
 
 namespace webrtc {
 
-LockedIsacBandwidthInfo::LockedIsacBandwidthInfo()
-      : lock_(CriticalSectionWrapper::CreateCriticalSection()) {
-  bwinfo_.in_use = 0;
+bool QpParser::GetQp(const VCMEncodedFrame& frame, int* qp) {
+  switch (frame.CodecSpecific()->codecType) {
+    case kVideoCodecVP8:
+      // QP range: [0, 127].
+      return vp8::GetQp(frame.Buffer(), frame.Length(), qp);
+    default:
+      return false;
+  }
 }
 
-LockedIsacBandwidthInfo::~LockedIsacBandwidthInfo() = default;
-
 }  // namespace webrtc