AGC2 component that computes and applies the digital gain. The gain is computed from an estimated speech and noise level. This component decides how fast the gain can change and what it should be. Bug: webrtc:7494 Change-Id: If55b6e5c765f958e433730cd9e3b2b93c14a7910 Reviewed-on: https://webrtc-review.googlesource.com/64985 Commit-Queue: Alex Loiko <aleloi@webrtc.org> Reviewed-by: Alessio Bazzica <alessiob@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22741}