Update database head.js to use sessionStorage.
Update database head.js to use sessionStorage.

BUG=68660
TEST=database page cycler goes green

Review URL: http://codereview.chromium.org/6057009

git-svn-id: http://src.chromium.org/svn/trunk/src@70567 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 63bcc7404ba28e6d0873a753e7a8587759441900
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser