Apple's attitude towards, and stewardship of, my privacy is worth a very serious markup to me personally. Doesn't hurt that the products are so good too.
/* to hide the native top tabs */
#TabsToolbar * {
visibility: collapse;
}
/* to give the top toolbar a bit of height so the window controls don't dangle off to the right */
#TabsToolbar:before {
content: '';
display: block;
width: 100%;
height: 20px;
}
/* to hide the sidebar header */
#sidebar-header {
visibility: collapse;
}