EDX-435: Delete DL buttons for video and transcript when users watch video by smartphone.
EDX-435: Delete DL buttons for video and transcript when users watch video by smartphone.

yokose-ks/edx-platform,yokose-ks/edx-platform,WatanabeYasumasa/edx-platform,yokose-ks/edx-platform,WatanabeYasumasa/edx-platform,yokose-ks/edx-platform,yokose-ks/edx-platform,WatanabeYasumasa/edx-platform,WatanabeYasumasa/edx-platform