Avoids crash in WebRTC audio clients for 96kHz render rate on Mac OSX.

content/renderer/media/webrtc_audio_renderer.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/renderer/media/webrtc_audio_renderer.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "content/renderer/media/audio_device_factory.h"
@@ skipping 142 matching lines @@
   if (base::win::GetVersion() < base::win::VERSION_VISTA) {
     buffer_size = 3 * buffer_size;
     DLOG(WARNING) << "Extending the output buffer size by a factor of three "
                   << "since Windows XP has been detected.";
   }
 #elif defined(OS_MACOSX)
   channel_layout = media::CHANNEL_LAYOUT_MONO;
 
   // Render side: AUDIO_PCM_LOW_LATENCY on Mac OS X is based on a callback-
   // driven Core Audio implementation. Tests have shown that 10ms is a suitable
-  // frame size to use, both for 48kHz and 44.1kHz.
+  // frame size to use for 96kHz, 48kHz and 44.1kHz.
 
   // Use different buffer sizes depending on the current hardware sample rate.
-  if (sample_rate == 48000) {
-    buffer_size = 480;
+  if (sample_rate == 96000 || sample_rate == 48000) {
+    buffer_size = (sample_rate / 100);
   } else {
     // We do run at 44.1kHz at the actual audio layer, but ask for frames
     // at 44.0kHz to ensure that we can feed them to the webrtc::VoiceEngine.
     buffer_size = 440;
   }
 #elif defined(OS_LINUX) || defined(OS_OPENBSD)
   channel_layout = media::CHANNEL_LAYOUT_MONO;
 
   // Based on tests using the current ALSA implementation in Chrome, we have
   // found that 10ms buffer size on the output side works fine.
@@ skipping 104 matching lines @@
                              params_.bits_per_sample() / 8);
   return audio_bus->frames();
 }
 
 void WebRtcAudioRenderer::OnRenderError() {
   NOTIMPLEMENTED();
   LOG(ERROR) << "OnRenderError()";
 }
 
 }  // namespace content