Add integration test for appendWindowEnd
Add integration test for appendWindowEnd

Safari 8 fails this new test because it has not implemented
appendWindowEnd.  Because of this, all of our multi-period
StreamingEngine integration tests fail.

This new test makes clear the root cause of the StreamingEngine
issues on Safari 8.

Safari 9 has implemented appendWindowEnd.

Change-Id: Id3684ca6addca196287a77e18fae47529e5b4778

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