Switch OnMoreData() to use AudioBus.

media/base/audio_bus.h

Index: media/base/audio_bus.h
diff --git a/media/base/audio_bus.h b/media/base/audio_bus.h
index ea7e5f81a5fb8f1a8eba59ced6e8ae2fb0c91730..544f7cbdfd1b8710010ce27f7b12bd1906226c53 100644
--- a/media/base/audio_bus.h
+++ b/media/base/audio_bus.h
@@ -66,7 +66,8 @@ class MEDIA_EXPORT AudioBus {
   void CopyTo(AudioBus* dest) const;
 
   // Returns a raw pointer to the requested channel.  Pointer is guaranteed to
-  // have a 16-byte alignment.
+  // have a 16-byte alignment.  Warning: Do not rely on having sane (i.e. not
+  // inf, nan, or between [-1.0, 1.0]) values in the channel data.
   float* channel(int channel) { return channel_data_[channel]; }
   const float* channel(int channel) const { return channel_data_[channel]; }