Merge r7729 into M40 branch.

BUG=chromium:436400
TBR=phoglund@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/27259004

git-svn-id: http://webrtc.googlecode.com/svn@7759 4adac7df-926f-26a2-2b94-8c16560cd09d
Move ChannelBuffer class to channel_buffer file

No change in functionallity.

BUG=webrtc:3146
R=andrew@webrtc.org, bjornv@webrtc.org, kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/28109004

git-svn-id: http://webrtc.googlecode.com/svn@7760 4adac7df-926f-26a2-2b94-8c16560cd09d
Make bands vector in SplittingFilter Analysis const

BUG=webrtc:3146
R=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/30229004

git-svn-id: http://webrtc.googlecode.com/svn@7761 4adac7df-926f-26a2-2b94-8c16560cd09d