Changing non-const reference arguments to pointers, ACM

Part of refactoring of ACM, and recent lint-warnings.
This CL changes non-const references in the ACM API to pointers.

BUG=issue1372

Review URL: https://webrtc-codereview.appspot.com/1103012

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3543 4adac7df-926f-26a2-2b94-8c16560cd09d
20 files changed