Audio related IPC messages and handlers from browser to renderer

media/audio/audio_output.h

 // Copyright (c) 2006-2008 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_OUTPUT_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_H_
 
 #include "base/basictypes.h"
 
 // Low-level audio output support. To make sound there are 3 objects involved:
@@ skipping 23 matching lines @@
 // The primary client of this facility is audio coming from several tabs.
 // Specifically for this case we avoid supporting complex formats such as MP3
 // or WMA. Complex format decoding should be done by the renderers.
 
 
 // Models an audio stream that gets rendered to the audio hardware output.
 // Because we support more audio streams than physically available channels
 // a given AudioOutputStream might or might not talk directly to hardware.
 class AudioOutputStream {
  public:
+  enum State {
+    STATE_STARTED = 0,  // The output stream is started.
+    STATE_PAUSED,       // The output stream is paused.
+    STATE_ERROR,        // The output stream is in error state.
+  };
+
   // Audio sources must implement AudioSourceCallback. This interface will be
   // called in a random thread which very likely is a high priority thread. Do
   // not rely on using this thread TLS or make calls that alter the thread
   // itself such as creating Windows or initializing COM.
   class AudioSourceCallback {
    public:
     virtual ~AudioSourceCallback() {}
 
     // Provide more data by filling |dest| up to |max_size| bytes. The provided
     // buffer size is usually what is specified in Open(). The source
@@ skipping 94 matching lines @@
   // TODO(cpu): Define threading requirements for interacting with AudioManager.
   static AudioManager* GetAudioManager();
 
  protected:
   virtual ~AudioManager() {}
 };
 
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_H_