Adding microphone volume support to chrome.

media/audio/linux/alsa_wrapper.h

Index: media/audio/linux/alsa_wrapper.h
diff --git a/media/audio/linux/alsa_wrapper.h b/media/audio/linux/alsa_wrapper.h
index 85cf68a5600e3a65d57192a6a48ece0e79d839c8..380b3a85ce4b0d79e947a8eeff2582a3b39e8c16 100644
--- a/media/audio/linux/alsa_wrapper.h
+++ b/media/audio/linux/alsa_wrapper.h
@@ -45,6 +45,27 @@ class MEDIA_EXPORT AlsaWrapper {
   virtual snd_pcm_state_t PcmState(snd_pcm_t* handle);
   virtual int PcmStart(snd_pcm_t* handle);
 
+  virtual int MixerOpen(snd_mixer_t** mixer, int mode);
+  virtual int MixerAttach(snd_mixer_t* mixer, const char* name);
+  virtual int MixerElementRegister(snd_mixer_t* mixer,
+                                   struct snd_mixer_selem_regopt* options,
+                                   snd_mixer_class_t** classp);
+  virtual void MixerFree(snd_mixer_t* mixer);
+  virtual int MixerDetach(snd_mixer_t* mixer, const char* name);
+  virtual int MixerClose(snd_mixer_t* mixer);
+  virtual int MixerLoad(snd_mixer_t* mixer);
+  virtual snd_mixer_elem_t* MixerFirstElem(snd_mixer_t* mixer);
+  virtual snd_mixer_elem_t* MixerNextElem(snd_mixer_elem_t* elem);
+  virtual int MixerSelemIsActive(snd_mixer_elem_t* elem);
+  virtual const char* MixerSelemName(snd_mixer_elem_t* elem);
+  virtual int MixerSelemSetCaptureVolumeAll(snd_mixer_elem_t* elem, long value);
+  virtual int MixerSelemGetCaptureVolume(snd_mixer_elem_t* elem,
+                                         snd_mixer_selem_channel_id_t channel,
+                                         long* value);
+  virtual int MixerSelemHasCaptureVolume(snd_mixer_elem_t* elem);
+  virtual int MixerSelemGetCaptureVolumeRange(snd_mixer_elem_t* elem,
+                                              long* min, long* max);
+
   virtual const char* StrError(int errnum);
 
  private: