RTCStatsReport: Take ownership of other's stats with TakeMembersFrom

webrtc/stats/rtcstatsreport.cc

Index: webrtc/stats/rtcstatsreport.cc
diff --git a/webrtc/stats/rtcstatsreport.cc b/webrtc/stats/rtcstatsreport.cc
index 870651d2dfc52b1afff2bda5f227ee57274c34ed..dc7a9917e54e6dc4931ac47602030dd001ef1562 100644
--- a/webrtc/stats/rtcstatsreport.cc
+++ b/webrtc/stats/rtcstatsreport.cc
@@ -73,6 +73,14 @@ const RTCStats* RTCStatsReport::operator[](const std::string& id) const {
   return nullptr;
 }
 
+void RTCStatsReport::Scavenge(rtc::scoped_refptr<RTCStatsReport> victim) {
+  for (StatsMap::iterator it = victim->stats_.begin();
+       it != victim->stats_.end(); ++it) {
+    AddStats(std::unique_ptr<const RTCStats>(it->second.release()));
+  }
+  victim->stats_.clear();
+}
+
 RTCStatsReport::ConstIterator RTCStatsReport::begin() const {
   return ConstIterator(rtc::scoped_refptr<const RTCStatsReport>(this),
                        stats_.cbegin());