This test tries to manipulate an iframe loaded via a data: URL. Since this is a different security context than the parent file:// URL and chromium enforces the check for file:// URLs, we can't manipulate the frame. Simple fix is to put the iframe contents in a file and load it.
Created attachment 30296 [details] move data url into a file
Created attachment 30297 [details] v2 Updated to include bug number.
Landed as http://trac.webkit.org/changeset/43713.