1. Embed an iframe which has scrollable content with a non-white background color.
2. Scroll the iframe partially out of the viewport.
3. Scroll the iframe itself.
This leads to scrolling errors like those shown in the attached screenshot.
Created attachment 135895 [details]
Failing version of the layout test output
Created attachment 135903 [details]
Comment on attachment 135903 [details]
Clearing flags on attachment: 135903
Committed r113386: <http://trac.webkit.org/changeset/113386>
All reviewed patches have been landed. Closing bug.