Reland of Unify rtcp packet setters

webrtc/modules/rtp_rtcp/source/rtcp_packet/fir.h

 /*
  *  Copyright (c) 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 18 matching lines @@
     uint32_t ssrc;
     uint8_t seq_nr;
   };
 
   Fir() {}
   ~Fir() override {}
 
   // Parse assumes header is already parsed and validated.
   bool Parse(const CommonHeader& packet);
 
-  void WithRequestTo(uint32_t ssrc, uint8_t seq_num) {
-    items_.push_back(Request(ssrc, seq_num));
+  void AddRequestTo(uint32_t ssrc, uint8_t seq_num) {
+    items_.emplace_back(ssrc, seq_num);
   }
   const std::vector<Request>& requests() const { return items_; }
 
  protected:
   bool Create(uint8_t* packet,
               size_t* index,
               size_t max_length,
               RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
   static constexpr size_t kFciLength = 8;
   size_t BlockLength() const override {
     return kHeaderLength + kCommonFeedbackLength + kFciLength * items_.size();
   }
   // SSRC of media source is not used in FIR packet. Shadow base functions.
-  void To(uint32_t ssrc);
+  void SetMediaSsrc(uint32_t ssrc);
   uint32_t media_ssrc() const;
 
   std::vector<Request> items_;
 };
 }  // namespace rtcp
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_FIR_H_