Reference test compositing/regions/position-layers-inside-regions-overflow-hidden.html is failing since it was introduced in r162605 <trac.webkit.org/changeset/162605> Test output differs insignificantly from expected result (difference can be seen after increasing contrast): http://build.webkit.org/results/EFL%20Linux%2064-bit%20Release%20WK2/r162930%20%2812674%29/compositing/regions/position-layers-inside-regions-overflow-hidden-diffs.html
Started to pass in r169784 - r169979 commit range: http://trac.webkit.org/log/?verbose=on&rev=169798&stop_rev=169784, probably after bumping EFL to 1.9 <http://trac.webkit.org/changeset/169785>