Stop playback on an unplayable period
Stop playback on an unplayable period

When we call this.onError_() directly, the load() pipeline will
continue even in a case where it should not.  By throwing the error
instead, we force load() to stop before issuing additional, confusing
errors.

b/34127751

Change-Id: I9c5e1412711b08407c976aeec2fcd01abcf73456

Ross-cz/shaka-player,Ross-cz/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,indiereign/shaka-player,vimond/shaka-player,indiereign/shaka-player,russitto/shaka-player,tvoli/shaka-player,TheModMaker/shaka-player,vimond/shaka-player,shaka-project/shaka-player,vimond/shaka-player,TobbeEdgeware/shaka-player,tvoli/shaka-player,brightcove/shaka-player,Ross-cz/shaka-player,TobbeEdgeware/shaka-player,tvoli/shaka-player,indiereign/shaka-player,brightcove/shaka-player,brightcove/shaka-player,russitto/shaka-player,TheModMaker/shaka-player,shaka-project/shaka-player,TheModMaker/shaka-player,TheModMaker/shaka-player,shaka-project/shaka-player,russitto/shaka-player,TobbeEdgeware/shaka-player