This is a version of bug 764076. (The dialog here is an intrinsically-sized element with
Not reproducible on Ubuntu and OSx platforms.
Sort of true -- the text doesn't get overlapped on those platforms, but that's only because the scrollbars are less wide on those platforms, and Yahoo does specify 16px of padding to the right of the text here, which provides some "breathing room". So, if your scrollbar is less than 16px wide (as it is on Ubuntu/Mac), then you won't see the text being covered up. But some of that padding does get covered up due to bug 764076 (whereas it doesn't get covered up in Chrome).