Switch audio synchronization from sleep() based to select() based.

media/audio/audio_parameters.h

Index: media/audio/audio_parameters.h
diff --git a/media/audio/audio_parameters.h b/media/audio/audio_parameters.h
index bc629a7db0033adb3a475e8a2f5d0e98bd5b438a..9b86d31186a7c2d33f6f0388b36a344f0855cd97 100644
--- a/media/audio/audio_parameters.h
+++ b/media/audio/audio_parameters.h
@@ -6,6 +6,7 @@
 #define MEDIA_AUDIO_AUDIO_PARAMETERS_H_
 
 #include "base/basictypes.h"
+#include "base/time/time.h"
 #include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 
@@ -69,6 +70,10 @@ class MEDIA_EXPORT AudioParameters {
   // Returns the number of bytes representing a frame of audio.
   int GetBytesPerFrame() const;
 
+  // Returns the duration of this buffer as calculated from frames_per_buffer()
+  // and sample_rate().
+  base::TimeDelta GetBufferDuration() const;
+
   Format format() const { return format_; }
   ChannelLayout channel_layout() const { return channel_layout_; }
   int sample_rate() const { return sample_rate_; }