Fix compile error introduced with r6571.

TBR=mflodman@webrtc.org

BUG=3527

Review URL: https://webrtc-codereview.appspot.com/20799004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6572 4adac7df-926f-26a2-2b94-8c16560cd09d