Disables Opera permutation

Opera uses webkit permutation with the recent Chromium based
versions and GWT will drop seperate Opera permutation in the
next release after 2.6.

Change-Id: Ifbde48ca3f41239cb3b19137b61c332cbddc334d
(cherry picked from commit 147ed73dd35de315379f0fc09920fef4a53d3606)