This CL solves the wraparound distortion in Opus.
In the Opus decoder-wrapper we are downsampling the signal from 48 kHz to 32 kHz. This is done in two steps, using the following functions from the signal processing library:
WebRtcSpl_Resample48khzTo32khz() and WebRtcSpl_VectorBitShiftW32ToW16
The latter does not have a saturation check, and the signal can suffer from wraparound. I've added saturation control to the function.
BUG=issue1089
Review URL: https://webrtc-codereview.appspot.com/967004
git-svn-id: http://webrtc.googlecode.com/svn/trunk@3103 4adac7df-926f-26a2-2b94-8c16560cd09d
53a8be20f1