Clean up audio-related utility functions to compute buffer sizes

content/browser/renderer_host/media/audio_renderer_host.cc

Index: content/browser/renderer_host/media/audio_renderer_host.cc
diff --git a/content/browser/renderer_host/media/audio_renderer_host.cc b/content/browser/renderer_host/media/audio_renderer_host.cc
index 75499467a2b63f0444c667073391f2525c747e54..2b6815a71774626ec7ee37415812f0c5b15e2756 100644
--- a/content/browser/renderer_host/media/audio_renderer_host.cc
+++ b/content/browser/renderer_host/media/audio_renderer_host.cc
@@ -199,12 +199,8 @@ void AudioRendererHost::OnCreateStream(
   DCHECK(LookupById(stream_id) == NULL);
 
   AudioParameters audio_params(params);
+  DCHECK_GT(audio_params.samples_per_packet, 0);
 
-  // Select the hardware packet size if not specified.
-  if (!audio_params.samples_per_packet) {
-    audio_params.samples_per_packet =
-        media::SelectSamplesPerPacket(audio_params.sample_rate);
-  }
   uint32 packet_size = audio_params.GetPacketSize();
 
   scoped_ptr<AudioEntry> entry(new AudioEntry());