This tests platform specific system font styles. If any of the styles appear in monospace the test fails.
caption: normal normal normal normal 16px/18px "Liberation Sans"
icon: normal normal normal normal 16px/18px "Liberation Sans"
menu: normal normal normal normal 16px/18px "Liberation Sans"
message-box: normal normal normal normal 16px/18px "Liberation Sans"
small-caption: normal normal normal normal 16px/18px "Liberation Sans"
status-bar: normal normal normal normal 16px/18px "Liberation Sans"
-webkit-mini-control: normal normal normal normal 16px/18px "Liberation Sans"
-webkit-small-control: normal normal normal normal 16px/18px "Liberation Sans"
-webkit-control: normal normal normal normal 16px/18px "Liberation Sans"