I made a mistake in r165872 that caused us to apply the device scale twice when snapshotting via scaledSnapshotWithOptions. <rdar://problem/16396629>
Created attachment 227697 [details] patch 1) We need snapshotting tests desperately, there are too many combinations of options to not have some tests. 2) I need to test WKThumbnailView before landing this.
http://trac.webkit.org/changeset/166203