The first step to add device selection to linux.

media/audio/linux/audio_manager_linux.h

Index: media/audio/linux/audio_manager_linux.h
===================================================================
--- media/audio/linux/audio_manager_linux.h	(revision 104076)
+++ media/audio/linux/audio_manager_linux.h	(working copy)
@@ -39,9 +39,23 @@
   virtual ~AudioManagerLinux();
 
  private:
-  // Helper method to query if there is any valid input device
-  bool HasAnyValidAudioInputDevice(void** hint);
+  enum StreamType {
+    kStreamPlayback = 0,
+    kStreamCapture,
+  };
 
+  // Get a list of available ALSA input devices.
+  void GetAlsaAudioInputDevices(media::AudioDeviceNames* device_names);
+
+  // Get the ALSA devices' information like names and ids.

[henrika (OOO until Aug 14), 2011/10/13 09:41:17]

Nit. We only get name and ID here. Not clear.

[no longer working on chromium, 2011/10/19 16:06:03]

Done.

+  void GetAlsaDevicesInfo(void** hint, media::AudioDeviceNames* device_names);
+
+  // Check if the specific ALSA device is available.
+  bool IsAlsaDeviceAvailable(const char* device_name);
+
+  // Query if there is any valid ALSA input device?

[henrika (OOO until Aug 14), 2011/10/13 09:41:17]

??

[scherkus (not reviewing), 2011/10/18 23:22:51]

this comment would be clearer if stated as "Returns true if a device is present
for the given stream type."

[no longer working on chromium, 2011/10/19 16:06:03]

Done.

[no longer working on chromium, 2011/10/19 16:06:03]

Done.

+  bool HasAnyAlsaAudioDevice(StreamType stream);
+
   scoped_ptr<AlsaWrapper> wrapper_;
 
   std::set<AudioOutputStream*> active_streams_;