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

media/audio/audio_parameters.h

Index: media/audio/audio_parameters.h
diff --git a/media/audio/audio_parameters.h b/media/audio/audio_parameters.h
index 244d8b9f0fb0cc3b7427ff939847d2b42a78ebb6..f532517ca850158c40c1e4f860f67f6d5250a10b 100644
--- a/media/audio/audio_parameters.h
+++ b/media/audio/audio_parameters.h
@@ -9,6 +9,19 @@
 #include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 
+struct MEDIA_EXPORT AudioInputBufferParameters {
+  double volume;
+  uint32 size;
+};
+
+// Use a struct-in-struct approach to ensure that we can calculate the required
+// size as sizeof(AudioInputBufferParameters) + #(bytes in audio buffer) without
+// using packing.
+struct MEDIA_EXPORT AudioInputBuffer {
+  AudioInputBufferParameters params;
+  int8 audio[1];
+};
+
 // TODO(vrk): This should probably be changed to an immutable object instead of
 // a struct. See crbug.com/115902.
 struct MEDIA_EXPORT AudioParameters {