This was originally filed as http://crbug.com/109888, see http://persistent.info/webkit/test-cases/crbug-109888.html for a reduction (the text "The body contents should be visible" should appear on a green background, instead the entire page is white). The appending of the stylesheet dynamically is something that the page did, the inserting of the (temporary) body tag is from jQuery pre-1.6.2 which was included in the page (originally via a Chrome extension, though that's not relevant, since it happens when done directly too).
Delightfully obscure.
Another regression from this change is http://stationstreetpgh.com/ (it should have pie charts that animate in, but they don't appear at all in WebKit nightlies post-r104060) So far, it seems to boil down to the "active" callback in Typekit's font loading code not firing (I've asked someone from their side if they can debug it). Here's a somewhat reduced test case: http://persistent.info/chromium/test-cases/crbug-112714/page.html It should display "loading" and then "active". In builds with the bug, it just displays "loading", and then eventually "inactive" (presumably a failure timeout firing).
Created attachment 129854 [details] patch
Comment on attachment 129854 [details] patch r=,e
trac.webkit.org/changeset/109543