Audio output debug recording.

media/audio/fake_audio_file_writer.h

Index: media/audio/fake_audio_file_writer.h
diff --git a/media/audio/fake_audio_file_writer.h b/media/audio/fake_audio_file_writer.h
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+// 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_FAKE_AUDIO_FILE_WRITER_H_
+#define MEDIA_AUDIO_FAKE_AUDIO_FILE_WRITER_H_
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "media/audio/audio_file_writer.h"
+#include "media/base/media_export.h"
+
+namespace media {
+
+// Creates fake AudioFileWriter that does nothing. Used by tests.
+class MEDIA_EXPORT FakeAudioFileWriter
+    : NON_EXPORTED_BASE(public AudioFileWriter) {
+ public:
+  FakeAudioFileWriter();
+  ~FakeAudioFileWriter() override;
+  void Start(const base::FilePath& file) override;
+  void Stop() override;
+  void Write(std::unique_ptr<AudioBus> data) override;
+  bool WillWrite() override;
+
+  // Simple create function that can be passed as a callback.
+  static std::unique_ptr<media::AudioFileWriter> Create(
+      const media::AudioParameters& params);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(FakeAudioFileWriter);
+};
+
+}  // namspace media
+
+#endif  // MEDIA_AUDIO_FAKE_AUDIO_FILE_WRITER_H_