Sometimes (if a window created on a 2x display tries to take a snapshot after being moved to a 1x display), the snapshot comes back at the wrong size (scaled up and blurry). To work around this for now, we can re-request the snapshot with a slightly different set of options which work in this case (but won't be correct if the bug isn't happening).
<rdar://problem/17087497>
<rdar://problem/17084993> tracks the underlying bug.
Created attachment 232316 [details] patch
http://trac.webkit.org/changeset/169510