This tests platform specific system font styles. If any of the styles appear in monospace the test fails.
caption: normal normal normal normal 12px/15px "Segoe UI"
icon: normal normal normal normal 12px/15px "Segoe UI"
menu: normal normal normal normal 12px/15px "Segoe UI"
message-box: normal normal normal normal 12px/15px "Segoe UI"
small-caption: normal normal normal normal 12px/15px "Segoe UI"
status-bar: normal normal normal normal 12px/15px "Segoe UI"
-webkit-mini-control: normal normal normal normal 13px/16px "MS Shell Dlg"
-webkit-small-control: normal normal normal normal 13px/16px "MS Shell Dlg"
-webkit-control: normal normal normal normal 13px/16px "MS Shell Dlg"