See bug 43504 for details and test case. This is about fixing the V8 bindings.
Once Chromium picks up the V8 change to allow allocations in the failed access check callback (code.google.com/p/v8/source/detail?r=5257), this should be pretty straightforward.
So, looks like the initial V8 bit rolled in, but it's still not possible to directly throw an exception from the FailedAccessCheckCallback. Filed http://code.google.com/p/v8/issues/detail?id=2524, I'll poke at the V8 folks once the next round of discussion on the topic goes somewhere.
no v8 bindings in webkit