Fix for Chrome (v 45) issue that key is sometimes undefined outside of the for-in loop.
Fix for Chrome (v 45) issue that key is sometimes undefined outside of the for-in loop.

mcanthony/openseadragon,avandecreme/openseadragon,jmnetus/openseadragon,TMUND/openseadragon,seanich/openseadragon,openseadragon/openseadragon,openseadragon/openseadragon,rdlester/openseadragon,rdlester/openseadragon,msalsbery/openseadragon,seanich/openseadragon,LarissaSmith/openseadragon,jmnetus/openseadragon,msalsbery/openseadragon,avandecreme/openseadragon,TMUND/openseadragon,mcanthony/openseadragon,LarissaSmith/openseadragon