Use the correct number of WaveOut buffers on XP...

media/audio/win/audio_manager_win.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 "media/audio/audio_io.h"
 
 #include <windows.h>
 #include <objbase.h>  // This has to be before initguid.h
 #include <initguid.h>
 #include <mmsystem.h>
@@ skipping 270 matching lines @@
 // - WASAPIAudioOutputStream: Based on Core Audio (WASAPI) API.
 AudioOutputStream* AudioManagerWin::MakeLowLatencyOutputStream(
     const AudioParameters& params) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
   if (params.channels() > kWinMaxChannels)
     return NULL;
 
   if (!CoreAudioUtil::IsSupported()) {
     // Fall back to Windows Wave implementation on Windows XP or lower.
     DVLOG(1) << "Using WaveOut since WASAPI requires at least Vista.";
-    return new PCMWaveOutAudioOutputStream(this, params, 2, WAVE_MAPPER);
+    return new PCMWaveOutAudioOutputStream(
+        this, params, media::NumberOfWaveOutBuffers(), WAVE_MAPPER);
   }
 
   // TODO(henrika): remove once we properly handle input device selection.
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableWebAudioInput)) {
     if (WASAPIUnifiedStream::HasUnifiedDefaultIO()) {
       DVLOG(1) << "WASAPIUnifiedStream is created.";
       return new WASAPIUnifiedStream(this, params);
     }
     LOG(WARNING) << "Unified audio I/O is not supported.";
@@ skipping 65 matching lines @@
     channel_layout = WASAPIAudioOutputStream::HardwareChannelLayout();
   }
 
   // TODO(dalecurtis): This should include hardware bits per channel eventually.
   return AudioParameters(
       AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
       sample_rate, bits_per_sample, GetAudioHardwareBufferSize());
 }
 
 }  // namespace media