Refactoring to share MockAudioOutputStream implementations across 3 platforms...

media/audio/win/audio_output_win.cc

Index: media/audio/win/audio_output_win.cc
===================================================================
--- media/audio/win/audio_output_win.cc	(revision 20503)
+++ media/audio/win/audio_output_win.cc	(working copy)
@@ -9,81 +9,10 @@
 
 #include "base/at_exit.h"
 #include "base/basictypes.h"
+#include "media/audio/fake_audio_output_stream.h"
 #include "media/audio/win/audio_manager_win.h"
 #include "media/audio/win/waveout_output_win.h"
 
-// A do-nothing audio stream. It behaves like a regular audio stream but does
-// not have any side effect, except possibly the creation and tear-down of
-// of a thread. It is useful to test code that uses audio streams such as
-// audio sources.
-class AudioOutputStreamMockWin : public AudioOutputStream {
- public:
-  explicit AudioOutputStreamMockWin(AudioManagerWin* manager)
-      : manager_(manager),
-        callback_(NULL),
-        buffer_(NULL),
-        packet_size_(0),
-        left_volume_(1.0),
-        right_volume_(1.0) {
-  }
-
-  virtual ~AudioOutputStreamMockWin() {
-    delete[] buffer_;
-    packet_size_ = 0;
-  }
-
-  virtual bool Open(size_t packet_size) {
-    if (packet_size < sizeof(int16))
-      return false;
-    packet_size_ = packet_size;
-    buffer_ = new char[packet_size_];
-    return true;
-  }
-
-  virtual void Start(AudioSourceCallback* callback)  {
-    callback_ = callback;
-    memset(buffer_, 0, packet_size_);
-    callback_->OnMoreData(this, buffer_, packet_size_);
-  }
-
-  // TODO(cpu): flesh out Start and Stop methods. We need a thread to
-  // perform periodic callbacks.
-  virtual void Stop() {
-  }
-
-  virtual void SetVolume(double left_level, double right_level) {
-    left_volume_ = left_level;
-    right_volume_ = right_level;
-  }
-
-  virtual void GetVolume(double* left_level, double* right_level) {
-    *left_level = left_volume_;
-    *right_level = right_volume_;
-  }
-
-  virtual size_t GetNumBuffers() {
-    return 1;
-  }
-
-  virtual void Close() {
-    callback_->OnClose(this);
-    callback_ = NULL;
-    manager_->ReleaseStream(this);
-  }
-
-  char* buffer() {
-    return buffer_;
-  }
-
- private:
-  AudioManagerWin* manager_;
-  AudioSourceCallback* callback_;
-  char* buffer_;
-  size_t packet_size_;
-  double left_volume_;
-  double right_volume_;
-};
-
 namespace {
 
 // The next 3 constants are some sensible limits to prevent integer overflow
@@ -93,18 +22,10 @@
 const int kMaxSampleRate = 192000;
 const int kMaxBitsPerSample = 64;
 
-AudioOutputStreamMockWin* g_last_mock_stream = NULL;
 AudioManagerWin* g_audio_manager = NULL;
 
-void ReplaceLastMockStream(AudioOutputStreamMockWin* newer) {
-  if (g_last_mock_stream)
-    delete g_last_mock_stream;
-  g_last_mock_stream = newer;
-}
-
 }  // namespace.
 
-
 bool AudioManagerWin::HasAudioDevices() {
   return (::waveOutGetNumDevs() != 0);
 }
@@ -113,7 +34,6 @@
 // should suffice most windows user's needs.
 // - PCMWaveOutAudioOutputStream: Based on the waveOutWrite API (in progress)
 // - PCMDXSoundAudioOutputStream: Based on DirectSound or XAudio (future work).
-
 AudioOutputStream* AudioManagerWin::MakeAudioStream(Format format, int channels,
                                                     int sample_rate,
                                                     char bits_per_sample) {
@@ -123,7 +43,7 @@
     return NULL;
 
   if (format == AUDIO_MOCK) {
-    return new AudioOutputStreamMockWin(this);
+    return FakeAudioOutputStream::MakeFakeStream();
   } else if (format == AUDIO_PCM_LINEAR) {
     return new PCMWaveOutAudioOutputStream(this, channels, sample_rate,
                                            bits_per_sample, WAVE_MAPPER);
@@ -136,15 +56,6 @@
     delete stream;
 }
 
-void AudioManagerWin::ReleaseStream(AudioOutputStreamMockWin *stream) {
-  // Note that we keep the last mock stream so GetLastMockBuffer() works.
-  ReplaceLastMockStream(stream);
-}
-
-const void* AudioManagerWin::GetLastMockBuffer() {
-  return (g_last_mock_stream) ? g_last_mock_stream->buffer() : NULL;
-}
-
 void AudioManagerWin::MuteAll() {
 }
 
@@ -152,7 +63,6 @@
 }
 
 AudioManagerWin::~AudioManagerWin() {
-  ReplaceLastMockStream(NULL);
 }
 
 void DestroyAudioManagerWin(void* param) {