Apply mask smoothing in Beamformer

This generates much more aggressive postfilter masks, which remove the interference and background noise better.

R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/35089004

Cr-Commit-Position: refs/heads/master@{#8315}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8315 4adac7df-926f-26a2-2b94-8c16560cd09d
2 files changed