GitLab

It looks up the current preference through DesktopNotificationService
and reports failures when it's stopped.

BUG=161094


Review URL: https://chromiumcodereview.appspot.com/12221127

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@182138 0039d316-1c4b-4281-b951-d872f2087c98