Per discussion with mal, recognize the stable branch (parent regkey present but no 'ap' child).  Also made recognizing beta/dev a touch more general.
Per discussion with mal, recognize the stable branch (parent regkey
present but no 'ap' child).  Also made recognizing beta/dev a touch
more general.

BUG=31772

Review URL: http://codereview.chromium.org/534005

git-svn-id: http://src.chromium.org/svn/trunk/src@35857 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: f168071514ef632364d6034b51c6ca31dce51939
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