Revert of Remove ignored return code from modules.

webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h

 /*
  *  Copyright (c) 2015 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 64 matching lines @@
       const std::vector<PacketInfo>& packet_feedback_vector) override;
 
   void IncomingPacket(int64_t arrival_time_ms,
                       size_t payload_size,
                       const RTPHeader& header,
                       bool was_paced) override;
   // This class relies on Process() being called periodically (at least once
   // every other second) for streams to be timed out properly. Therefore it
   // shouldn't be detached from the ProcessThread except if it's about to be
   // deleted.
-  void Process() override;
+  int32_t Process() override;
   int64_t TimeUntilNextProcess() override;
   void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) override;
   void RemoveStream(uint32_t ssrc) override;
   bool LatestEstimate(std::vector<uint32_t>* ssrcs,
                       uint32_t* bitrate_bps) const override;
   void SetMinBitrate(int min_bitrate_bps) override;
 
  private:
   typedef std::map<uint32_t, int64_t> Ssrcs;
   enum class ProbeResult { kBitrateUpdated, kNoUpdate };
@@ skipping 40 matching lines @@
   Ssrcs ssrcs_ GUARDED_BY(&crit_);
   AimdRateControl remote_rate_ GUARDED_BY(&crit_);
   Clock* const clock_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RemoteBitrateEstimatorAbsSendTime);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_REMOTE_BITRATE_ESTIMATOR_ABS_SEND_TIME_H_