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

BUG=2119
R=mflodman@webrtc.org

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

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 735a7c8b9322bc544159faf4cec0915fa5644fd0

sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc