Merge AudioRendererImpl and AudioRendererBase; add NullAudioSink

content/renderer/media/audio_input_device.h

Index: content/renderer/media/audio_input_device.h
diff --git a/content/renderer/media/audio_input_device.h b/content/renderer/media/audio_input_device.h
index f7427e86c3885e133021337999d134ff70e0710d..01198669f5ef672d8775ceb647c789c67a360313 100644
--- a/content/renderer/media/audio_input_device.h
+++ b/content/renderer/media/audio_input_device.h
@@ -94,8 +94,8 @@ class CONTENT_EXPORT AudioInputDevice
   class CONTENT_EXPORT CaptureCallback {
    public:
     virtual void Capture(const std::vector<float*>& audio_data,
-                         size_t number_of_frames,
-                         size_t audio_delay_milliseconds) = 0;
+                         int number_of_frames,
+                         int audio_delay_milliseconds) = 0;
     virtual void OnCaptureError() = 0;
    protected:
     virtual ~CaptureCallback() {}
@@ -146,7 +146,7 @@ class CONTENT_EXPORT AudioInputDevice
     return audio_parameters_.sample_rate();
   }
 
-  size_t buffer_size() const {
+  int buffer_size() const {
     return audio_parameters_.frames_per_buffer();
   }