Fix bug introduced during replace of list wrapper with std equivalents in r5378. R=henrika@webrtc.org, pbos@webrtc.org, henrike@webrtc.org TBR=henrike@webrtc.org BUG=2164 Review URL: https://webrtc-codereview.appspot.com/7639004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@5437 4adac7df-926f-26a2-2b94-8c16560cd09d