Docserver: Make ContentProviders continuing runnings its Cron method even if
some ContentProvider instances fail. GitHub Crons are a bit flaky (e.g.
susceptible to out-of-quota errors) and we don't want to fail the whole server
updating in that case.

TBR=yoz@chromium.org

Review URL: https://codereview.chromium.org/112133006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240380 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240380