RTCStatsReport: Take ownership of other's stats with TakeMembersFrom

webrtc/api/rtcstatsreport.h

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 37 matching lines @@
     rtc::scoped_refptr<const RTCStatsReport> report_;
     StatsMap::const_iterator it_;
   };
 
   static rtc::scoped_refptr<RTCStatsReport> Create();
 
   RTCStatsReport();
   RTCStatsReport(const RTCStatsReport& other) = delete;
 
   bool AddStats(std::unique_ptr<const RTCStats> stats);
-  const RTCStats* operator[](const std::string& id) const;
+  const RTCStats* Get(const std::string& id) const;
   size_t size() const { return stats_.size(); }
 
+  // Takes ownership of all the stats in |victim|, leaving it empty.
+  void TakeMembersFrom(rtc::scoped_refptr<RTCStatsReport> victim);
+
+  // Stats iterators. Stats are ordered lexicographically on |RTCStats::id|.
   ConstIterator begin() const;
   ConstIterator end() const;
 
   // Gets the subset of stats that are of type |T|, where |T| is any class
   // descending from |RTCStats|.
   template<typename T>
   std::vector<const T*> GetStatsOfType() const {
     std::vector<const T*> stats_of_type;
     for (const RTCStats& stats : *this) {
       if (stats.type() == T::kType)
         stats_of_type.push_back(&stats.cast_to<const T>());
     }
     return stats_of_type;
   }
 
   friend class rtc::RefCountedObject<RTCStatsReport>;
 
  private:
   ~RTCStatsReport() override;
 
   StatsMap stats_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_RTCSTATSREPORT_H_