Created attachment 244208 [details] Screenshot showing different behavior between Mac and Windows. The test case "fast/writing-mode/broken-ideograph-small-caps.html" indicates that Windows does not properly draw text in vertical-rl mode. See screenshot.
See http://dev.w3.org/csswg/css-writing-modes-3/#text-orientation for some motivation. It looks like neither port is doing the right thing.
<rdar://problem/19405094>
See related Bug 140220.