Clean up audio-related utility functions to compute buffer sizes

content/browser/renderer_host/media/audio_renderer_host.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/media/audio_renderer_host.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
@@ skipping 181 matching lines @@
 
   return handled;
 }
 
 void AudioRendererHost::OnCreateStream(
     int stream_id, const AudioParameters& params) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   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());
 
   // Create the shared memory and share with the renderer process.
   uint32 shared_memory_size =
       media::TotalSharedMemorySizeInBytes(packet_size);
   if (!entry->shared_memory.CreateAndMapAnonymous(shared_memory_size)) {
     // If creation of shared memory failed then send an error message.
     SendErrorMessage(stream_id);
@@ skipping 170 matching lines @@
   }
   return NULL;
 }
 
 content::MediaObserver* AudioRendererHost::GetMediaObserver() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (!media_observer_)
     media_observer_ = resource_context_->GetMediaObserver();
   return media_observer_;
 }