8160974: [TESTBUG] Mark more headful tests with @key headful.
Reviewed-by: serb, simonis

8150844: [hidpi] [macosx] -Dsun.java2d.uiScale should be taken into account for OS X
Reviewed-by: serb, avstepan

8150258: [TEST] HiDPI: create a test for multiresolution menu items icons
Reviewed-by: serb, yan