This marks 4 gradient-related tests previously marked as failing on Mac
as failing on only 10.5 and 10.6, since they pass on 10.7.
It also marks one Arabic-shaping-related test as failing, for which bug
705044 has been filed.
This patch was created by running the following sed commands:
s/MOZ_WIDGET_TOOLKIT=="\(gtk2\|cocoa\|qt\|windows\)"/\1Widget/g
s/MOZ_WIDGET_TOOLKIT!="\(gtk2\|cocoa\|qt\|windows\)"/!\1Widget/g
on all *.list files in the tree.