Add back a constructor to fix FYI build.
Add back a constructor to fix FYI build.

TBR=perkj

Review URL: https://webrtc-codereview.appspot.com/24349005

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@7854 4adac7df-926f-26a2-2b94-8c16560cd09d

TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc