Adds Analog Gain Control (AGC) to the WebRTC client.

media/audio/win/wavein_input_win.h

Index: media/audio/win/wavein_input_win.h
diff --git a/media/audio/win/wavein_input_win.h b/media/audio/win/wavein_input_win.h
index a9b4b913dfb9cec2cf243ff6b867dd6341140908..b4418d86beb83a5a62b18504e0484ade88a8049b 100644
--- a/media/audio/win/wavein_input_win.h
+++ b/media/audio/win/wavein_input_win.h
@@ -5,6 +5,8 @@
 #ifndef MEDIA_AUDIO_WIN_WAVEIN_INPUT_WIN_H_
 #define MEDIA_AUDIO_WIN_WAVEIN_INPUT_WIN_H_
 
+#include <string>
+
 #include <windows.h>
 #include <mmsystem.h>
 
@@ -36,6 +38,8 @@ class PCMWaveInAudioInputStream : public AudioInputStream {
   virtual double GetMaxVolume() OVERRIDE;
   virtual void SetVolume(double volume) OVERRIDE;
   virtual double GetVolume() OVERRIDE;
+  virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
+  virtual bool GetAutomaticGainControl() OVERRIDE;
 
  private:
   enum State {