84d4c57544
In the test_classify_by_default.html, we use "network.cookie.cookieBehavior" to test if a channel is correctly classified. Cookie restriction is only enabled in nightly and early beta so the default preference is not always set. Although we set the preference in the testcase, it is too late because that the channel's cookie setting might inherit from it's parent and may end up with getting the old(default) value. In this patch, we use window.open to test the tracker frame to make sure we use the udpated prefrence. Differential Revision: https://phabricator.services.mozilla.com/D25657