NTP: Make sure that hidden elements cannot be dragged.
NTP: Make sure that hidden elements cannot be dragged.

BUG=34124
TEST=Hide thumbnails on NTP. Reload. Make sure you cannot drag the hidden thumbnails.

Review URL: http://codereview.chromium.org/568006

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@37860 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser