Revert of MediaStream audio object graph untangling and clean-ups.

content/renderer/media/media_recorder_handler.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/media_recorder_handler.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 117 matching lines @@
   blink::WebVector<blink::WebMediaStreamTrack> video_tracks, audio_tracks;
   media_stream_.videoTracks(video_tracks);
   media_stream_.audioTracks(audio_tracks);
 
   if (video_tracks.isEmpty() && audio_tracks.isEmpty()) {
     LOG(WARNING) << __FUNCTION__ << ": no media tracks.";
     return false;
   }
 
   const bool use_audio_tracks =
-      !audio_tracks.isEmpty() && MediaStreamAudioTrack::From(audio_tracks[0]);
+      !audio_tracks.isEmpty() &&
+      MediaStreamAudioTrack::GetTrack(audio_tracks[0]);
 
   webm_muxer_.reset(new media::WebmMuxer(
       use_vp9_ ? media::kCodecVP9 : media::kCodecVP8,
       video_tracks.size() > 0, use_audio_tracks,
       base::Bind(&MediaRecorderHandler::WriteData,
                  weak_factory_.GetWeakPtr())));
 
   if (!video_tracks.isEmpty()) {
     // TODO(mcasas): The muxer API supports only one video track. Extend it to
     // several video tracks, see http://crbug.com/528523.
@@ skipping 111 matching lines @@
     recorder->OnData(audio_bus, timestamp);
 }
 
 void MediaRecorderHandler::SetAudioFormatForTesting(
     const media::AudioParameters& params) {
   for (auto* recorder : audio_recorders_)
     recorder->OnSetFormat(params);
 }
 
 }  // namespace content