Adds support for 16kHz input sample rate and mono channel config. in WebRTC.

media/audio/win/audio_low_latency_input_win.h

Index: media/audio/win/audio_low_latency_input_win.h
diff --git a/media/audio/win/audio_low_latency_input_win.h b/media/audio/win/audio_low_latency_input_win.h
index ebaab9307b0943b3a33a09f06ee825b5948b061e..e236e4415c2f1e92f42aac5d82a7d4630061e9f0 100644
--- a/media/audio/win/audio_low_latency_input_win.h
+++ b/media/audio/win/audio_low_latency_input_win.h
@@ -89,10 +89,14 @@ class MEDIA_EXPORT WASAPIAudioInputStream
   virtual void Stop() OVERRIDE;
   virtual void Close() OVERRIDE;
 
-  // Retrieves the stream format that the audio engine uses for its internal
+  // Retrieves the sample rate used by the audio engine for its internal
   // processing/mixing of shared-mode streams.
   static double HardwareSampleRate(ERole device_role);
 
+  // Retrieves the number of audio channels used by the audio engine for its
+  // internal processing/mixing of shared-mode streams.
+  static uint32 HardwareChannelCount(ERole device_role);
+
   bool started() const { return started_; }
 
  private:
@@ -109,6 +113,10 @@ class MEDIA_EXPORT WASAPIAudioInputStream
   bool DesiredFormatIsSupported();
   HRESULT InitializeAudioEngine();
 
+  // Retrieves the stream format that the audio engine uses for its internal
+  // processing/mixing of shared-mode streams.
+  static HRESULT GetMixFormat(ERole device_role, WAVEFORMATEX** device_format);
+
   // Initializes the COM library for use by the calling thread and set the
   // thread's concurrency model to multi-threaded.
   base::win::ScopedCOMInitializer com_init_;