Moved the fake input stream's processing onto the audio worker thread.

media/audio/simple_sources.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 MEDIA_AUDIO_SIMPLE_SOURCES_H_
 #define MEDIA_AUDIO_SIMPLE_SOURCES_H_
 
+#include "base/files/file_path.h"
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_io.h"
+#include "media/base/audio_converter.h"
 #include "media/base/seekable_buffer.h"
 
 namespace media {
 
+class WavAudioHandler;
+
+class SimpleSource : public AudioOutputStream::AudioSourceCallback {

[DaleCurtis, 2015/02/19 19:54:54]

Why is this necessary? Open() is only used in the FileSource() and it's
definitely something you could just call on the first OnMoreData().

[phoglund_chromium, 2015/02/20 14:22:00]

All right.

+ public:
+  ~SimpleSource() override {};
+
+  virtual void Open() {}
+};
+
 // An audio source that produces a pure sinusoidal tone.
-class MEDIA_EXPORT SineWaveAudioSource
-    : public AudioOutputStream::AudioSourceCallback {
+class MEDIA_EXPORT SineWaveAudioSource : public SimpleSource {
  public:
   // |channels| is the number of audio channels, |freq| is the frequency in
   // hertz and it has to be less than half of the sampling frequency
   // |sample_freq| or else you will get aliasing.
   SineWaveAudioSource(int channels, double freq, double sample_freq);
   ~SineWaveAudioSource() override {}
 
   // Return up to |cap| samples of data via OnMoreData().  Use Reset() to
   // allow more data to be served.
   void CapSamples(int cap);
@@ skipping 10 matching lines @@
  protected:
   int channels_;
   double f_;
   int time_state_;
   int cap_;
   int callbacks_;
   int errors_;
   base::Lock time_lock_;
 };
 
+class FileSource : public SimpleSource,
+                   public AudioConverter::InputCallback{

[DaleCurtis, 2015/02/19 19:54:54]

Space after InputCallback

[phoglund_chromium, 2015/02/20 14:22:00]

Done.

+ public:
+  FileSource(const AudioParameters& params,
+             const base::FilePath& path_to_wav_file);
+  ~FileSource() override;
+
+  void Open() override;
+
+  // Implementation of AudioSourceCallback.
+  int OnMoreData(AudioBus* audio_bus, uint32 total_bytes_delay) override;
+  void OnError(AudioOutputStream* stream) override {}
+
+ private:
+  AudioParameters params_;
+  base::FilePath path_to_wav_file_;
+  scoped_ptr<uint8[]> wav_file_data_;
+  scoped_ptr<media::WavAudioHandler> wav_audio_handler_;

[DaleCurtis, 2015/02/19 19:54:54]

No need for media:: prefix on anything in this .h or .cc

[phoglund_chromium, 2015/02/20 14:22:00]

Done.

+  scoped_ptr<media::AudioConverter> file_audio_converter_;
+  int wav_file_read_pos_;
+  int buffer_size_;
+
+  // Provides audio data from wav_audio_handler_ into the file audio converter.
+  double ProvideInput(AudioBus* audio_bus,
+                      base::TimeDelta buffer_delay) override;
+};
+
+class BeepingSource : public SimpleSource {
+ public:
+  BeepingSource(const AudioParameters& params);
+  ~BeepingSource() override;
+
+  // Implementation of AudioSourceCallback.
+  int OnMoreData(AudioBus* audio_bus, uint32 total_bytes_delay) override;
+  void OnError(AudioOutputStream* stream) override {}

[DaleCurtis, 2015/02/19 19:54:54]

Inline methods aren't allowed for virtual functions, so you'll need to define
these in the .cc . Ditto for the rest in this class.

[phoglund_chromium, 2015/02/20 14:22:00]

Done.

[phoglund_chromium, 2015/02/20 14:22:00]

Done.

+
+  static void BeepOnce();
+ private:
+  scoped_ptr<uint8[]> buffer_;
+  int buffer_size_;
+  AudioParameters params_;
+  base::TimeTicks last_callback_time_;
+  base::TimeDelta interval_from_last_beep_;
+  int beep_duration_in_buffers_;
+  int beep_generated_in_buffers_;
+  int beep_period_in_frames_;
+};
+
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_SIMPLE_SOURCES_H_