Add Singleton traits for a "leaky singleton" - one that does not clean up at exit.
Add Singleton traits for a "leaky singleton" - one that does
not clean up at exit.

Review URL: http://codereview.chromium.org/13069

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@6303 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