Allow pass through buffer sizes on OSX.

media/base/audio_hardware_config.cc

 // Copyright (c) 2013 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 "media/base/audio_hardware_config.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "build/build_config.h"
 
 using base::AutoLock;
 using media::AudioParameters;
 
 namespace media {
 
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_MACOSX)
 #define HIGH_LATENCY_AUDIO_SUPPORT 1
 #endif
 
 #if defined(HIGH_LATENCY_AUDIO_SUPPORT)
 // Taken from "Bit Twiddling Hacks"
 // http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
 static uint32_t RoundUpToPowerOfTwo(uint32_t v) {
   v--;
   v |= v >> 1;
   v |= v >> 2;
@@ skipping 91 matching lines @@
   // dependent but will generally be sample_rate() / 100.
   const int high_latency_buffer_size =
       RoundUpToPowerOfTwo(2 * output_params_.sample_rate() / 100);
   return std::max(output_params_.frames_per_buffer(), high_latency_buffer_size);
 #else
   return output_params_.frames_per_buffer();
 #endif
 }
 
 }  // namespace media