Revert of MediaStream audio: Refactor 3 separate "glue" implementations into one.

content/renderer/media/webaudio_media_stream_source.h

-// 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.
-
-#ifndef CONTENT_RENDERER_MEDIA_WEBAUDIO_MEDIA_STREAM_SOURCE_H_
-#define CONTENT_RENDERER_MEDIA_WEBAUDIO_MEDIA_STREAM_SOURCE_H_
-
-#include <memory>
-
-#include "base/time/time.h"
-#include "content/renderer/media/media_stream_audio_source.h"
-#include "media/base/audio_bus.h"
-#include "media/base/audio_push_fifo.h"
-#include "third_party/WebKit/public/platform/WebAudioDestinationConsumer.h"
-#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
-#include "third_party/WebKit/public/platform/WebVector.h"
-
-namespace content {
-
-// Implements the WebAudioDestinationConsumer interface to provide a source of
-// audio data (i.e., the output from a graph of WebAudio nodes) to one or more
-// MediaStreamAudioTracks. Audio data is transported directly to the tracks in
-// 10 ms chunks.
-class WebAudioMediaStreamSource final
-    : NON_EXPORTED_BASE(public MediaStreamAudioSource),
-      public blink::WebAudioDestinationConsumer {
- public:
-  explicit WebAudioMediaStreamSource(blink::WebMediaStreamSource* blink_source);
-
-  ~WebAudioMediaStreamSource() override;
-
- private:
-  // WebAudioDestinationConsumer implementation.
-  //
-  // Note: Blink ensures setFormat() and consumeAudio() are not called
-  // concurrently across threads, but these methods could be called on any
-  // thread.
-  void setFormat(size_t number_of_channels, float sample_rate) override;
-  void consumeAudio(const blink::WebVector<const float*>& audio_data,
-                    size_t number_of_frames) override;
-
-  // Called by AudioPushFifo zero or more times during the call to
-  // consumeAudio().  Delivers audio data with the required buffer size to the
-  // tracks.
-  void DeliverRebufferedAudio(const media::AudioBus& audio_bus,
-                              int frame_delay);
-
-  // MediaStreamAudioSource implementation.
-  bool EnsureSourceIsStarted() final;
-  void EnsureSourceIsStopped() final;
-
-  // In debug builds, check that all methods that could cause object graph
-  // or data flow changes are being called on the main thread.
-  base::ThreadChecker thread_checker_;
-
-  // True while this WebAudioMediaStreamSource is registered with
-  // |blink_source_| and is consuming audio.
-  bool is_registered_consumer_;
-
-  // A wrapper used for providing audio to |fifo_|.
-  std::unique_ptr<media::AudioBus> wrapper_bus_;
-
-  // Takes in the audio data passed to consumeAudio() and re-buffers it into 10
-  // ms chunks for the tracks. This ensures each chunk of audio delivered to
-  // the tracks has the required buffer size, regardless of the amount of audio
-  // provided via each consumeAudio() call.
-  media::AudioPushFifo fifo_;
-
-  // Used to pass the reference timestamp between DeliverDecodedAudio() and
-  // DeliverRebufferedAudio().
-  base::TimeTicks current_reference_time_;
-
-  // This object registers with a blink::WebMediaStreamSource. We keep track of
-  // that in order to be able to deregister before stopping this source.
-  blink::WebMediaStreamSource blink_source_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebAudioMediaStreamSource);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_WEBAUDIO_MEDIA_STREAM_SOURCE_H_