Delete Chrome extensions related registry entries on uninstall.
Delete Chrome extensions related registry entries on uninstall.

BUG=7178

Review URL: http://codereview.chromium.org/58019


git-svn-id: http://src.chromium.org/svn/trunk/src@13414 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 1f33acdfca7f6367c8cc25a10283205c8d753a1a
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