Revert of Remove ignored return code from modules.

webrtc/video/vie_sync_module.h

 /*
  *  Copyright (c) 2012 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 22 matching lines @@
   explicit ViESyncModule(VideoCodingModule* vcm);
   ~ViESyncModule();
 
   void ConfigureSync(int voe_channel_id,
                      VoEVideoSync* voe_sync_interface,
                      RtpRtcp* video_rtcp_module,
                      RtpReceiver* video_receiver);
 
   // Implements Module.
   int64_t TimeUntilNextProcess() override;
-  void Process() override;
+  int32_t Process() override;
 
  private:
   rtc::CriticalSection data_cs_;
   VideoCodingModule* const vcm_;
   RtpReceiver* video_receiver_;
   RtpRtcp* video_rtp_rtcp_;
   int voe_channel_id_;
   VoEVideoSync* voe_sync_interface_;
   TickTime last_sync_time_;
   rtc::scoped_ptr<StreamSynchronization> sync_;
   StreamSynchronization::Measurements audio_measurement_;
   StreamSynchronization::Measurements video_measurement_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_VIE_SYNC_MODULE_H_