GitLab

By default LMU disabled for managed devices.

Also added support of new policy in ChromeOS part.

BUG=229298

Review URL: https://chromiumcodereview.appspot.com/17546004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207978 0039d316-1c4b-4281-b951-d872f2087c98