Implement AudioOutputProxy.

media/audio/audio_manager.h

 // Copyright (c) 2010 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_MANAGER_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_H_
 
 #include "base/basictypes.h"
 #include "base/string16.h"
 #include "media/audio/audio_parameters.h"
@@ skipping 36 matching lines @@
   //
   // |params.format| can be set to AUDIO_PCM_LOW_LATENCY and that has two
   // effects:
   // 1- Instead of triple buffered the audio will be double buffered.
   // 2- A low latency driver or alternative audio subsystem will be used when
   //    available.
   //
   // Do not free the returned AudioOutputStream. It is owned by AudioManager.
   virtual AudioOutputStream* MakeAudioOutputStream(AudioParameters params) = 0;
 
+  // Creates new audio output proxy. A proxy implements
+  // AudioOutputStream inteface, but unlike regular output stream

[scherkus (not reviewing), 2010/11/24 02:01:59]

nit: inteface -> interface

[Sergey Ulanov, 2010/11/24 03:49:54]

Done.

+  // created with MakeAudioOutputStream() it opens device only when a
+  // sound is actually playing.
+  virtual AudioOutputStream* MakeAudioOutputStreamProxy(
+      const AudioParameters& params) = 0;
+
   // Factory to create audio recording streams.
   // |channels| can be 1 or 2.
   // |sample_rate| is in hertz and can be any value supported by the platform.
   // |bits_per_sample| can be any value supported by the platform.
   // |samples_per_packet| is in hertz as well and can be 0 to |sample_rate|,
   // with 0 suggesting that the implementation use a default value for that
   // platform.
   // Returns NULL if the combination of the parameters is not supported, or if
   // we have reached some other platform specific limit.
   //
@@ skipping 20 matching lines @@
   virtual void Init() = 0;
 
  private:
   static void Destroy(void*);
 
   // Called by GetAudioManager() to create platform-specific audio manager.
   static AudioManager* CreateAudioManager();
 };
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_H_