Fixing IsZeroSize call
Fixing IsZeroSize call

Review URL: https://webrtc-codereview.appspot.com/940004

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: a5d4c31735efb0dbc4f6c675ea57398ccdc208fa

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