Add back is.FrameProvider() call lost in r4194.

BUG=2119
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1946004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4480 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed