Increase Windows XP hardware buffer size to 4096.

media/audio/win/waveout_output_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/win/waveout_output_win.h"
 
 #include <windows.h>
 #include <mmsystem.h>
 #pragma comment(lib, "winmm.lib")
 
@@ skipping 266 matching lines @@
     HandleError(res);
     return;
   }
 
   // waveOutReset() leaves buffers in the unpredictable state, causing
   // problems if we want to close, release, or reuse them. Fix the states.
   for (int ix = 0; ix != num_buffers_; ++ix) {
     GetBuffer(ix)->dwFlags = WHDR_PREPARED;
   }
 
-  // Don't use callback after Stop().
+  // Don't use callback after Stop().  Wait for lock to ensure all outstanding
+  // callbacks have completed.
+  base::AutoLock auto_lock(lock_);

[Chris Rogers, 2012/11/15 22:49:30]

maybe this auto_lock should be moved up to just above line 281?

[DaleCurtis, 2012/11/15 22:58:23]

Done.

   callback_ = NULL;
 
   state_ = PCMA_READY;
 }
 
 // We can Close in any state except that trying to close a stream that is
 // playing Windows generates an error. We cannot propagate it to the source,
 // as callback_ is set to NULL. Just print it and hope somebody somehow
 // will find it...
 void PCMWaveOutAudioOutputStream::Close() {
@@ skipping 106 matching lines @@
                                        buffer,
                                        sizeof(WAVEHDR));
       if (result != MMSYSERR_NOERROR)
         stream->HandleError(result);
       stream->pending_bytes_ += buffer->dwBufferLength;
     }
   }
 }
 
 }  // namespace media