BrowsingContext.findWithName is required to do access checks based on the
requestor, which can only be done in the process which owns it. This change
also alters the behavior of the existing CanAccess origin checks, which
typically treat any item as same-origin, but only when the docshells are
actually same process.
Removing the exemption fixes the behavior discrepancy between Fission and
non-Fission runs, but also requires that the test be updated to expect proper
access checks. Which is the situation we really want to test, anyway.
Differential Revision: https://phabricator.services.mozilla.com/D45837
--HG--
extra : moz-landing-system : lando
