Audio output debug recording.

media/audio/audio_debug_recording_helper.h

+// Copyright 2017 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_AUDIO_AUDIO_DEBUG_RECORDING_HELPER_H_
+#define MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_HELPER_H_
+
+#include <memory>
+
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "media/audio/audio_file_writer.h"
+
+namespace base {
+class FilePath;
+class SingleThreadTaskRunner;
+}
+
+namespace media {
+
+class AudioBus;
+class AudioManager;
+
+// A helper class for objects that want to use AudioFileWriter. It handles
+// copying AudioBus data, thread jump (MaybeWrite() can be called on any
+// thread), and creating and deleting the AudioFileWriter at enable and disable.
+class AudioDebugRecordingHelper {

[o1ka, 2017/01/20 11:36:26]

Switch AudioInputController to using this as well? (Otherwise we have code
duplication.)

[o1ka, 2017/01/25 17:47:00]

Ping?

[Henrik Grunell, 2017/01/26 10:25:09]

Good point. I'll do that.

+ public:
+  AudioDebugRecordingHelper(
+      AudioManager* audio_manager,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  ~AudioDebugRecordingHelper();
+
+  // Enable and disable debug recording. When enabled, |audio_manager_| is asked
+  // to create a DebugWriter. Extension "wav" will be added to |file_name|.
+  void EnableDebugRecording(const AudioParameters& params,
+                            const base::FilePath& file_name);
+  void DisableDebugRecording();
+
+  // If debug recording is enabled, copies audio data and posts DoWrite() on
+  // |task_runner_|. Can be called on any thread.
+  void MaybeWrite(const AudioBus* source);
+
+  // Pass-through to AudioFileWriter::WillWrite(). Can be called on any thread.
+  bool WillWrite();
+
+ private:
+  // Writes debug data to |debug_writer_|.
+  void DoWrite(std::unique_ptr<media::AudioBus> data);
+
+  AudioManager* audio_manager_;
+  std::unique_ptr<AudioFileWriter> debug_writer_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;

[o1ka, 2017/01/20 11:36:26]

Add a comment what |task_runner_| is for?

[Henrik Grunell, 2017/01/26 10:25:09]

Done.

+
+  base::WeakPtrFactory<AudioDebugRecordingHelper> weak_factory_;
+  DISALLOW_COPY_AND_ASSIGN(AudioDebugRecordingHelper);
+};
+
+}  // namspace media
+
+#endif  // MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_HELPER_H_