removed chrome 21 bug in media comments
removed chrome 21 bug in media comments

fixes CNVS-5974

Change-Id: Id5371fcfb004b57733bf9b107cef9e837802ff81
Reviewed-on: https://gerrit.instructure.com/20885
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Stanley Stuart <2b43fb8b7a234825d50dd49ce7892d78a59da8f3@instructure.com>
QA-Review: Myller de Araujo <e5c7c5e1b7f2ce5e9870cc98ec52b20b3006cb48@instructure.com>
Product-Review: Ryan Florence <2d8900489f91ac272fd9ce9d5789db6522668ca2@instructure.com>

loganrun/pincan,narigone/canvas,whalejasmine/canvas-lms,shidao-fm/canvas-lms,instructure/canvas-lms,samuels410/greatlakes-lms,samuels410/greatlakes-lms,sdeleon28/canvas-lms,samuels410/greatlakes-lms,djbender/canvas-lms,wrdsb/canvas-lms,Rvor/canvas-lms,leftplusrightllc/canvas-lms,arrivu/jigsaw-lms,djbender/canvas-lms,sfu/canvas-lms,landonwilkins/canvas-lms,sfu/canvas-lms,Rvor/canvas-lms,antoniuslin/canvas-lms,dgynn/canvas-lms,efrj/canvas-lms,usmschuck/canvas,va7map/canvas-lms,fronteerio/canvas-lms,ShreniiNepal/shrenii_lmp,usmschuck/canvas,wrdsb/canvas-lms,wye0220/shindig-canvas,samuels410/greatlakes-lms,kyroskoh/canvas-lms,utkarshx/canvas-lms,grahamb/canvas-lms,loganrun/pincan,Rvor/canvas-lms,fronteerio/canvas-lms,venturehive/canvas-lms,Jyaasa/canvas-lms,SwinburneOnline/canvas-lms,fronteerio/canvas-lms,eCNAP/CANVAS,kyroskoh/canvas-lms,tgroshon/canvas-lms,ShreniiNepal/shrenii_lmp,sfu/canvas-lms,eCNAP/CANVAS,HotChalk/canvas-lms,snehakachroo1/LSI_replica,leftplusrightllc/canvas-lms,Jyaasa/canvas-lms,narigone/canvas,shidao-fm/canvas-lms,utkarshx/canvas-lms,fronteerio/canvas-lms,grahamb/canvas-lms,AndranikMarkosyan/lms,kyroskoh/canvas-lms,redconfetti/canvas-lms,dgynn/canvas-lms,sdeleon28/canvas-lms,Jyaasa/canvas-lms,usmschuck/canvas,shidao-fm/canvas-lms,redconfetti/canvas-lms,sfu/canvas-lms,whalejasmine/canvas-lms,va7map/canvas-lms,sfu/canvas-lms,matematikk-mooc/canvas-lms,wye0220/shindig-canvas,utkarshx/canvas-lms,jay3126/canvas-lms,loganrun/pincan,gbleydon/canvas-lms,Unow/canvas-lms,arrivu/jigsaw-lms,antoniuslin/canvas-lms,venturehive/canvas-lms,roxolan/canvas-lms,roxolan/canvas-lms,gbleydon/canvas-lms,eCNAP/CANVAS,greyhwndz/canvas-lms,AndranikMarkosyan/lms,sfu/canvas-lms,greyhwndz/canvas-lms,skmezanul/canvas-lms,merichar/canvas-lms,grahamb/canvas-lms,jay3126/canvas-lms,landonwilkins/canvas-lms,venturehive/canvas-lms,wimemx/Canvas,HotChalk/canvas-lms,narigone/canvas,snehakachroo1/LSI_replica,djbender/canvas-lms,instructure/canvas-lms,antoniuslin/canvas-lms,arrivu/jigsaw-lms,djbender/canvas-lms,SwinburneOnline/canvas-lms,jay3126/canvas-lms,snehakachroo1/LSI_replica,tgroshon/canvas-lms,landonwilkins/canvas-lms,SwinburneOnline/canvas-lms,greyhwndz/canvas-lms,snehakachroo1/LSI_replica,va7map/canvas-lms,arrivu/hoodemo,wrdsb/canvas-lms,skmezanul/canvas-lms,dgynn/canvas-lms,narigone/canvas,merichar/canvas-lms,venturehive/canvas-lms,arrivu/arrivu-lms,arrivu/arrivu-lms,instructure/canvas-lms,Rvor/canvas-lms,instructure/canvas-lms,wimemx/Canvas,eCNAP/CANVAS,wimemx/Canvas,matematikk-mooc/canvas-lms,leftplusrightllc/canvas-lms,instructure/canvas-lms,utkarshx/canvas-lms,arrivu/hoodemo,HotChalk/canvas-lms,usmschuck/canvas,tgroshon/canvas-lms,arrivu/hoodemo,whalejasmine/canvas-lms,wrdsb/canvas-lms,Unow/ins,AndranikMarkosyan/lms,wye0220/shindig-canvas,arrivu/qibla-ecampus,juoni/canvas-lms,roxolan/canvas-lms,whalejasmine/canvas-lms,antoniuslin/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,SwinburneOnline/canvas-lms,redconfetti/canvas-lms,va7map/canvas-lms,tgroshon/canvas-lms,sdeleon28/canvas-lms,efrj/canvas-lms,sdeleon28/canvas-lms,leftplusrightllc/canvas-lms,skmezanul/canvas-lms,Unow/ins,arrivu/qibla-ecampus,kyroskoh/canvas-lms,juoni/canvas-lms,redconfetti/canvas-lms,matematikk-mooc/canvas-lms,arrivu/arrivu-lms,Unow/ins,merichar/canvas-lms,matematikk-mooc/canvas-lms,skmezanul/canvas-lms,jay3126/canvas-lms,efrj/canvas-lms,roxolan/canvas-lms,Unow/canvas-lms,grahamb/canvas-lms,efrj/canvas-lms,instructure/canvas-lms,ShreniiNepal/shrenii_lmp,ShreniiNepal/shrenii_lmp,landonwilkins/canvas-lms,greyhwndz/canvas-lms,Unow/canvas-lms,shidao-fm/canvas-lms,Jyaasa/canvas-lms,juoni/canvas-lms,arrivu/qibla-ecampus,grahamb/canvas-lms,AndranikMarkosyan/lms,juoni/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,gbleydon/canvas-lms