A workaround for Opus DTX noise pumping issue was made according upon this https://codereview.webrtc.org/1422213003 Recently, Opus has fixed this problem internally, and hence the workaround is not needed any longer. This CL removes this workaround. BUG=586175 R=flim@webrtc.org, tina.legrand@webrtc.org Review URL: https://codereview.webrtc.org/1715423002 . Cr-Commit-Position: refs/heads/master@{#11805}