Implement writing mic audio input data to file for debugging purposes.

content/browser/renderer_host/media/audio_input_debug_writer.h

+// Copyright 2015 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_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_DEBUG_WRITER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_DEBUG_WRITER_H_
+
+#include "base/files/file.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "media/audio/audio_input_writer.h"
+
+namespace media {
+
+class AudioBus;
+class AudioBusRefCounted;
+
+}  // namespace media
+
+namespace content {
+
+// Writes audio input data used for debugging purposes. Can be created on any
+// thread. Must be destroyed on the FILE thread. Write call can be made on any
+// thread. This object must be unregistered in Write caller before destroyed.
+// When created, it takes ownership of |file|.
+class AudioInputDebugWriter : public media::AudioInputWriter {
+ public:
+  explicit AudioInputDebugWriter(base::File file);
+  ~AudioInputDebugWriter() override;
+
+  // Write data from |data| to file.
+  void Write(scoped_ptr<media::AudioBus> data) override;
+
+ private:
+  void DoWrite(scoped_ptr<media::AudioBus> data);
+
+  base::File file_;
+
+  scoped_ptr<char[]> interleaved_data_;
+  int interleaved_data_size_;
+
+  base::WeakPtrFactory<AudioInputDebugWriter> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioInputDebugWriter);
+};
+
+}  // namspace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_DEBUG_WRITER_H_