Add a virtual beamforming audio device on ChromeOS.

content/public/common/media_stream_request.h

Index: content/public/common/media_stream_request.h
diff --git a/content/public/common/media_stream_request.h b/content/public/common/media_stream_request.h
index b60835ee04b71aec95d53e2eb859432fdb52c62b..cafc22b66dac3c1afd0f164c8fdb67e88d986ae7 100644
--- a/content/public/common/media_stream_request.h
+++ b/content/public/common/media_stream_request.h
@@ -13,6 +13,7 @@
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
+#include "media/audio/audio_parameters.h"
 #include "ui/gfx/native_widget_types.h"
 #include "url/gurl.h"
 
@@ -126,17 +127,12 @@ struct CONTENT_EXPORT MediaStreamDevice {
   // Contains properties that match directly with those with the same name
   // in media::AudioParameters.
   struct AudioDeviceParameters {

[ajm, 2015/09/02 06:47:01]

This should probably _be_ a media::AudioParameters. I added a checkdeps
exception for this to make that clear.

I'll add a TODO on myself here if you agree, but would prefer not to make the
change in this CL.

[tommi (sloooow) - chröme, 2015/09/02 07:43:07]

I agree.  It's basically a poor man's copy of it.  The reason this is here
though is that we got push back for adding AudioParameters here way back when. 
We started out with only needing a couple of parameters, but things have grown
quite a bit since then.

If you'd like to fix this (not in this cl), then that would be great.

[ajm, 2015/09/02 17:00:55]

I'll add the TODO.

-    AudioDeviceParameters()
-        : sample_rate(), channel_layout(), frames_per_buffer(), effects() {
-    }
-
-    AudioDeviceParameters(int sample_rate, int channel_layout,
-        int frames_per_buffer)
-        : sample_rate(sample_rate),
-          channel_layout(channel_layout),
-          frames_per_buffer(frames_per_buffer),
-          effects() {
-    }
+    AudioDeviceParameters();
+    AudioDeviceParameters(int sample_rate,
+                          int channel_layout,
+                          int frames_per_buffer);
+
+    ~AudioDeviceParameters();
 
     // Preferred sample rate in samples per second for the device.
     int sample_rate;
@@ -154,6 +150,8 @@ struct CONTENT_EXPORT MediaStreamDevice {
 
     // See media::AudioParameters::PlatformEffectsMask.
     int effects;
+
+    std::vector<media::Point> mic_positions;
   };
 
   // These below two member variables are valid only when the type of device is