Make OS audio buffer size limits visible.

media/base/audio_latency.h

 // Copyright 2016 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.
 
 #ifndef MEDIA_BASE_AUDIO_LATENCY_H_
 #define MEDIA_BASE_AUDIO_LATENCY_H_
 
 #include "media/base/media_export.h"
 
 namespace base {
@@ skipping 25 matching lines @@
                                       int preferred_buffer_size);
 
   // |hardware_buffer_size| should be set to 0 if unknown/invalid/not preferred.
   static int GetRtcBufferSize(int sample_rate, int hardware_buffer_size);
 
   static int GetInteractiveBufferSize(int hardware_buffer_size);
 
   static int GetExactBufferSize(base::TimeDelta duration,
                                 int sample_rate,
                                 int hardware_buffer_size);
+
+  static int GetMinimumAudioBufferSize(int sample_rate);
+  static int GetMaximumAudioBufferSize(int sample_rate);
+  static int GetDefaultAudioBufferSize(bool is_input, int sample_rate);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_LATENCY_H_