Collapse AudioRendererMixer and OnMoreDataResampler into AudioTransform.

media/base/audio_pull_fifo.h

Index: media/base/audio_pull_fifo.h
diff --git a/media/base/audio_pull_fifo.h b/media/base/audio_pull_fifo.h
index 9fd3a8e1740c461864cf41dfc6bc0ce83ecc3816..06b7921a4d889ffb821862dc43954d538df7792e 100644
--- a/media/base/audio_pull_fifo.h
+++ b/media/base/audio_pull_fifo.h
@@ -39,6 +39,10 @@ class MEDIA_EXPORT AudioPullFifo {
   // Empties the FIFO without deallocating any memory.
   void Clear();
 
+  // Number of output frames already processed.  Can be called by ReadCB to
+  // determine the current audio delay due to buffering.
+  int output_frames_ready() { return output_frames_ready_; }
+
  private:
   // Attempt to fulfill the request using what is available in the FIFO.
   // Append new data to the |destination| starting at |write_pos|.
@@ -54,6 +58,8 @@ class MEDIA_EXPORT AudioPullFifo {
   // Temporary audio bus to hold the data from the producer.
   scoped_ptr<AudioBus> bus_;
 
+  int output_frames_ready_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioPullFifo);
 };