Currently the Qt port uses different default fonts than other browsers.
Committed r64114: <http://trac.webkit.org/changeset/64114>
<cherry-pick-for-backport: r64115>
<cherry-pick-for-backport: r64116>
<cherry-pick-for-backport: r64119>
Revision r64114 cherry-picked into qtwebkit-2.1 with commit deff3755bf1841f5f599fa2c90d53df7da0bbb27 Revision r64115 cherry-picked into qtwebkit-2.1 with commit 37346b4c38d98505b6e56b8d9072a696864b7a70 Revision r64116 cherry-picked into qtwebkit-2.1 with commit acb2ef3cba3b47ca0618cd5c9a0b96ffbac81b7b Revision r64119 cherry-picked into qtwebkit-2.1 with commit c74cf23e70a10bce2ddda6962e9d0b30f694fb10