This CL ensures that the AGC2 is created and initialized only when needed. Apart from that, the CL also avoids a runtime-reallocation that happens each time the setting is applied. Bug: webrtc:5298 Change-Id: Iad9eaa05a3d0baa0788cd11b2aa17ddd8e0c509b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/163987 Commit-Queue: Per Åhgren <peah@webrtc.org> Reviewed-by: Sam Zackrisson <saza@webrtc.org> Cr-Commit-Position: refs/heads/master@{#30139}