Remove various IDs

modules/audio_mixer/frame_combiner.cc

 /*
  *  Copyright (c) 2017 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 175 matching lines @@
   // Frames could be both stereo and mono.
   for (auto* frame : mix_list) {
     RemixFrame(number_of_channels, frame);
   }
 
   // TODO(aleloi): Issue bugs.webrtc.org/3390.
   // Audio frame timestamp. The 'timestamp_' field is set to dummy
   // value '0', because it is only supported in the one channel case and
   // is then updated in the helper functions.
   audio_frame_for_mixing->UpdateFrame(
-      -1, 0, nullptr, samples_per_channel, sample_rate, AudioFrame::kUndefined,
+      0, nullptr, samples_per_channel, sample_rate, AudioFrame::kUndefined,
       AudioFrame::kVadUnknown, number_of_channels);
 
   const bool use_limiter_this_round = use_apm_limiter_ && number_of_streams > 1;
 
   if (mix_list.empty()) {
     CombineZeroFrames(use_limiter_this_round, limiter_.get(),
                       audio_frame_for_mixing);
   } else if (mix_list.size() == 1) {
     CombineOneFrame(mix_list.front(), use_limiter_this_round, limiter_.get(),
                     audio_frame_for_mixing);
   } else {
     std::vector<rtc::ArrayView<const int16_t>> input_frames;
     for (size_t i = 0; i < mix_list.size(); ++i) {
       input_frames.push_back(rtc::ArrayView<const int16_t>(
           mix_list[i]->data(), samples_per_channel * number_of_channels));
     }
     CombineMultipleFrames(input_frames, use_limiter_this_round, limiter_.get(),
                           audio_frame_for_mixing);
   }
 }
 
 }  // namespace webrtc