add audio-buffer-size command line flag support to the input audio for all the platforms

media/audio/alsa/audio_manager_alsa.h

Index: media/audio/alsa/audio_manager_alsa.h
diff --git a/media/audio/alsa/audio_manager_alsa.h b/media/audio/alsa/audio_manager_alsa.h
index d08c3ba1f27cdc98264f090178f599eea22b702c..90298d9a9d28c34f9faf562e2b71f23421aa9923 100644
--- a/media/audio/alsa/audio_manager_alsa.h
+++ b/media/audio/alsa/audio_manager_alsa.h
@@ -29,8 +29,6 @@ class MEDIA_EXPORT AudioManagerAlsa : public AudioManagerBase {
       AudioDeviceNames* device_names) OVERRIDE;
   virtual void GetAudioOutputDeviceNames(
       AudioDeviceNames* device_names) OVERRIDE;
-  virtual AudioParameters GetInputStreamParameters(
-      const std::string& device_id) OVERRIDE;
 
   // Implementation of AudioManagerBase.
   virtual AudioOutputStream* MakeLinearOutputStream(
@@ -49,6 +47,9 @@ class MEDIA_EXPORT AudioManagerAlsa : public AudioManagerBase {
   virtual AudioParameters GetPreferredOutputStreamParameters(
       const std::string& output_device_id,
       const AudioParameters& input_params) OVERRIDE;
+  virtual AudioParameters GetPreferredInputStreamParameters(
+      const std::string& input_device_id,
+      const AudioParameters& input_params) OVERRIDE;
 
  private:
   enum StreamType {