Revert of Remove ignored return code from modules.

webrtc/modules/rtp_rtcp/include/receive_statistics.h

 /*
  *  Copyright (c) 2013 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 72 matching lines @@
 class NullReceiveStatistics : public ReceiveStatistics {
  public:
   void IncomingPacket(const RTPHeader& rtp_header,
                       size_t packet_length,
                       bool retransmitted) override;
   void FecPacketReceived(const RTPHeader& header,
                          size_t packet_length) override;
   StatisticianMap GetActiveStatisticians() const override;
   StreamStatistician* GetStatistician(uint32_t ssrc) const override;
   int64_t TimeUntilNextProcess() override;
-  void Process() override;
+  int32_t Process() override;
   void SetMaxReorderingThreshold(int max_reordering_threshold) override;
   void RegisterRtcpStatisticsCallback(
       RtcpStatisticsCallback* callback) override;
   void RegisterRtpStatisticsCallback(
       StreamDataCountersCallback* callback) override;
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_RTP_RTCP_INCLUDE_RECEIVE_STATISTICS_H_