Delete unused AudioBusRefCounted structure.

media/base/audio_bus.cc

 // Copyright (c) 2012 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 "media/base/audio_bus.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
@@ skipping 326 matching lines @@
   }
 }
 
 void AudioBus::SwapChannels(int a, int b) {
   DCHECK(a < channels() && a >= 0);
   DCHECK(b < channels() && b >= 0);
   DCHECK_NE(a, b);
   std::swap(channel_data_[a], channel_data_[b]);
 }
 
-scoped_refptr<AudioBusRefCounted> AudioBusRefCounted::Create(
-    int channels, int frames) {
-  return scoped_refptr<AudioBusRefCounted>(
-      new AudioBusRefCounted(channels, frames));
-}
-
-AudioBusRefCounted::AudioBusRefCounted(int channels, int frames)
-    : AudioBus(channels, frames) {}
-
-AudioBusRefCounted::~AudioBusRefCounted() {}
-
 }  // namespace media