Empty callback added to prevent crash for  application cache delete all
Empty callback added to prevent crash for  application cache delete all

Issue: CBWEBVIEW-317
Change-Id: I48cc96fc1b97246facda1f7cfb2d85f9d4f7e239

hgl888/chromium-efl,hgl888/chromium-efl,hgl888/chromium-efl,crosswalk-project/chromium-efl,hgl888/chromium-efl,crosswalk-project/chromium-efl,hgl888/chromium-efl,crosswalk-project/chromium-efl,crosswalk-project/chromium-efl