Revert of r8378 "Switch to using AudioEncoderIsac instead of ACMISAC"

This is a speculative revert to try to isolate a memory issue.

BUG=chromium:459483,4228
R=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/39189004

Cr-Commit-Position: refs/heads/master@{#8412}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8412 4adac7df-926f-26a2-2b94-8c16560cd09d
5 files changed