GitLab

The signals coming currently via DNSObserver are too noisy. DnsConfigService
can weed out false positives, so switch to using it exclusively.

BUG=142138
TEST=network requests work after network changes


Review URL: https://chromiumcodereview.appspot.com/10830271

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151278 0039d316-1c4b-4281-b951-d872f2087c98