Replace WebAudio MediaCodec usage with FFmpeg. A ~4x improvement.

media/base/android/webaudio_media_codec_info.h

-// Copyright 2013 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.
-
-#ifndef MEDIA_BASE_ANDROID_WEBAUDIO_MEDIA_CODEC_INFO_H_
-#define MEDIA_BASE_ANDROID_WEBAUDIO_MEDIA_CODEC_INFO_H_
-
-namespace media {
-
-// This structure holds the information about the audio file
-// determined by MediaCodec that is needed by the audio decoder to
-// create the necessary destination bus.
-struct WebAudioMediaCodecInfo {
-  unsigned long channel_count;
-  unsigned long sample_rate;
-  unsigned long number_of_frames;
-};
-
-}  // namespace media
-#endif // MEDIA_BASE_ANDROID_WEBAUDIO_MEDIA_CODEC_INFO_H_