Reduce LS_INFO spam from voice_engine/.

webrtc/voice_engine/transmit_mixer.cc

 /*
  *  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 627 matching lines @@
     return 0;
 }
 
 int TransmitMixer::StopPlayingFileAsMicrophone()
 {
     WEBRTC_TRACE(kTraceInfo, kTraceVoice, VoEId(_instanceId,-1),
                  "TransmitMixer::StopPlayingFileAsMicrophone()");
 
     if (!_filePlaying)
     {
-        _engineStatisticsPtr->SetLastError(
-            VE_INVALID_OPERATION, kTraceWarning,
-            "StopPlayingFileAsMicrophone() isnot playing");
         return 0;
     }
 
     CriticalSectionScoped cs(&_critSect);
 
     if (_filePlayerPtr->StopPlayingFile() != 0)
     {
         _engineStatisticsPtr->SetLastError(
             VE_CANNOT_STOP_PLAYOUT, kTraceError,
             "StopPlayingFile() couldnot stop playing file");
@@ skipping 676 matching lines @@
 void TransmitMixer::EnableStereoChannelSwapping(bool enable) {
   swap_stereo_channels_ = enable;
 }
 
 bool TransmitMixer::IsStereoChannelSwappingEnabled() {
   return swap_stereo_channels_;
 }
 
 }  // namespace voe
 }  // namespace webrtc