Always wait for DataReady() on Windows WaveOut.

media/audio/audio_io.h

 // 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.
 
 #ifndef MEDIA_AUDIO_AUDIO_IO_H_
 #define MEDIA_AUDIO_AUDIO_IO_H_
 
 #include "base/basictypes.h"
 #include "media/audio/audio_buffers_state.h"
 #include "media/base/audio_bus.h"
@@ skipping 56 matching lines @@
                              AudioBus* dest,
                              AudioBuffersState buffers_state) = 0;
 
     // There was an error while playing a buffer. Audio source cannot be
     // destroyed yet. No direct action needed by the AudioStream, but it is
     // a good place to stop accumulating sound data since is is likely that
     // playback will not continue. |code| is an error code that is platform
     // specific.
     virtual void OnError(AudioOutputStream* stream, int code) = 0;
 
-    // Waits till data becomes available. Used when buffering data starting
-    // new audio stream.
-    // Polling is not the best approach, but incorporating messaging loop
-    // with delayed tasks into guts of complex code is even worse, as it is
-    // very error-prone. We cannot easily add synchronization, interface is
-    // already cut in stone because of need of backward compatibility with
-    // plugins. In any case, data is usually immediately available,
-    // so there would be no delay.
+    // Deprecated.  DO NOT USE.  Waits until data becomes available.  Used only
+    // by Window's WaveOut clients which may be extremely laggy.  Will yield the

[scherkus (not reviewing), 2012/11/21 21:37:57]

nit: Windows'

[DaleCurtis, 2012/11/21 22:42:10]

Done.

+    // current thread until the renderer client has written its audio data.
     virtual void WaitTillDataReady() {}
 
    protected:
     virtual ~AudioSourceCallback() {}
   };
 
   virtual ~AudioOutputStream() {}
 
   // Open the stream. false is returned if the stream cannot be opened.  Open()
   // must always be followed by a call to Close() even if Open() fails.
@@ skipping 80 matching lines @@
   // Sets the Automatic Gain Control (AGC) state.
   virtual void SetAutomaticGainControl(bool enabled) = 0;
 
   // Returns the Automatic Gain Control (AGC) state.
   virtual bool GetAutomaticGainControl() = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_IO_H_