Add a media constraint to enable beamforming.

content/renderer/media/media_stream_audio_processor_options.cc

Index: content/renderer/media/media_stream_audio_processor_options.cc
diff --git a/content/renderer/media/media_stream_audio_processor_options.cc b/content/renderer/media/media_stream_audio_processor_options.cc
index 5f99c921d3ff133f9a0223fe674838afb2edcb56..8108cdf3d251def918eecd28189d2dbb699f0276 100644
--- a/content/renderer/media/media_stream_audio_processor_options.cc
+++ b/content/renderer/media/media_stream_audio_processor_options.cc
@@ -35,6 +35,7 @@ const char MediaAudioConstraints::kGoogNoiseSuppression[] =
     "googNoiseSuppression";
 const char MediaAudioConstraints::kGoogExperimentalNoiseSuppression[] =
     "googNoiseSuppression2";
+const char MediaAudioConstraints::kGoogBeamforming[] = "googBeamforming";
 const char MediaAudioConstraints::kGoogHighpassFilter[] = "googHighpassFilter";
 const char MediaAudioConstraints::kGoogTypingNoiseDetection[] =
     "googTypingNoiseDetection";
@@ -62,6 +63,7 @@ struct {
   { MediaAudioConstraints::kGoogHighpassFilter, true },
   { MediaAudioConstraints::kGoogTypingNoiseDetection, true },
   { MediaAudioConstraints::kGoogExperimentalNoiseSuppression, false },
+  { MediaAudioConstraints::kGoogBeamforming, false },
 #if defined(OS_WIN)
   { kMediaStreamAudioDucking, true },
 #else