New module for the adaptive level controlling functionality in the audio processing module

NOTRY=true
TBR=aluebs@webrtc.org
BUG=webrtc:5920

Review-Url: https://codereview.webrtc.org/2090583002
Cr-Original-Commit-Position: refs/heads/master@{#13333}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: ca4cac7e7494e7b5d60bda4b21b6a00592f8e1df
39 files changed