Adds method to invoke platform provided audio input UI.

media/audio/audio_manager.h

Index: media/audio/audio_manager.h
diff --git a/media/audio/audio_manager.h b/media/audio/audio_manager.h
index 2afc78902f9680a5096390ea04e8a4f483fa76de..3a570ad888bfc36d27da8cd65bdc3aa585c9b8ef 100644
--- a/media/audio/audio_manager.h
+++ b/media/audio/audio_manager.h
@@ -34,6 +34,16 @@ class AudioManager {
   // 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.
   //