Add case to ApmTest.Process to test the extended filter mode

R=andrew@webrtc.org, bjornv@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/40509004

Cr-Commit-Position: refs/heads/master@{#8192}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8192 4adac7df-926f-26a2-2b94-8c16560cd09d
5 files changed