Adds method to invoke platform provided audio input UI.

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 "base/task.h"
 #include "media/audio/audio_parameters.h"
 
 class AudioInputStream;
 class AudioOutputStream;
 class MessageLoop;
 
 // TODO(sergeyu): In this interface and some other places AudioParameters struct
 // is passed by value. It is better to change it to const reference.
 
 // Manages all audio resources. In particular it owns the AudioOutputStream
 // objects. Provides some convenience functions that avoid the need to provide
 // iterators over the existing streams.
 class AudioManager {
  public:
   // Returns true if the OS reports existence of audio devices. This does not
   // guarantee that the existing devices support all formats and sample rates.
   virtual bool HasAudioOutputDevices() = 0;
 
   // Returns true if the OS reports existence of audio recording devices. This
   // does not guarantee that the existing devices support all formats and
   // sample rates.
   virtual bool HasAudioInputDevices() = 0;
 
   // Returns a human readable string for the model/make of the active audio
   // input device for this computer.
   virtual string16 GetAudioInputDeviceModel() = 0;
 
+  // Returns true if the platform specific audio input settings UI is known
+  // and can be shown.
+  virtual bool CanShowAudioInputSettings() = 0;
+
+  // Opens the platform default audio input settings UI.
+  // Note: This could invoke an external application/preferences pane, so
+  // ideally must not be called from the UI thread or other time sensitive
+  // threads to avoid blocking the rest of the application.
+  virtual void ShowAudioInputSettings() = 0;
+
   // Factory for all the supported stream formats. |params| defines parameters
   // of the audio stream to be created.
   //
   // |params.sample_per_packet| is the requested buffer allocation which the
   // audio source thinks it can usually fill without blocking. Internally two
   // or three buffers are created, one will be locked for playback and one will
   // be ready to be filled in the call to AudioSourceCallback::OnMoreData().
   //
   // Returns NULL if the combination of the parameters is not supported, or if
   // we have reached some other platform specific limit.
@@ skipping 49 matching lines @@
   // Called by Destroy() to cleanup the instance before destruction.
   virtual void Cleanup() = 0;
 
  private:
   static void Destroy(void*);
 
   // Called by GetAudioManager() to create platform-specific audio manager.
   static AudioManager* CreateAudioManager();
 };
 
+DISABLE_RUNNABLE_METHOD_REFCOUNT(AudioManager);
+
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_H_