Add more disclaimers to extension install dialog.
Add more disclaimers to extension install dialog.

Review URL: http://codereview.chromium.org/184017

git-svn-id: http://src.chromium.org/svn/trunk/src@25207 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 49958a53daf17df5d90f6f719615d517f2a7ed1c
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