NetEq4: Making a few more members scoped_ptrs

This CL converts a few members in NetEqImpl form regular pointers
to scoped_ptrs.

R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2245004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4783 4adac7df-926f-26a2-2b94-8c16560cd09d
2 files changed