Introduce PPB_AudioInput_Dev v0.3 and refactor the device enumeration code:

ppapi/cpp/dev/audio_input_dev.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 PPAPI_CPP_DEV_AUDIO_INPUT_DEV_H_
 #define PPAPI_CPP_DEV_AUDIO_INPUT_DEV_H_
 
 #include <vector>
 
 #include "ppapi/c/dev/ppb_audio_input_dev.h"
@@ skipping 19 matching lines @@
   /// Static function for determining whether the browser supports the required
   /// AudioInput interface.
   ///
   /// @return true if the interface is available, false otherwise.
   static bool IsAvailable();
 
   int32_t EnumerateDevices(
       const CompletionCallbackWithOutput<std::vector<DeviceRef_Dev> >&
           callback);
 
+  int32_t MonitorDeviceChange(PP_MonitorDeviceChangeCallback callback,
+                              void* user_data);
+
   /// If |device_ref| is null (i.e., is_null() returns true), the default device
   /// will be used.
   int32_t Open(const DeviceRef_Dev& device_ref,
                const AudioConfig& config,
                PPB_AudioInput_Callback audio_input_callback,
                void* user_data,
                const CompletionCallback& callback);
 
   bool StartCapture();
   bool StopCapture();
   void Close();
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_DEV_AUDIO_INPUT_DEV_H_